Include cppcodec instead of using it a system library. Its not available in ubuntu repos for example

4 files changed, 938 insertions, 0 deletions

diff --git a/external/cppcodec/detail/base64.hpp b/external/cppcodec/detail/base64.hpp
new file mode 100644
index 0000000..b6db6d7
--- /dev/null
+++ b/external/cppcodec/detail/base64.hpp
@@ -0,0 +1,132 @@
+/**
+ *  Copyright (C) 2015 Topology LP
+ *  Copyright (C) 2013 Adam Rudd (bit calculations)
+ *  Copyright (C) 2018 Jakob Petsovits
+ *  All rights reserved.
+ *
+ *  Permission is hereby granted, free of charge, to any person obtaining a copy
+ *  of this software and associated documentation files (the "Software"), to
+ *  deal in the Software without restriction, including without limitation the
+ *  rights to use, copy, modify, merge, publish, distribute, sublicense, and/or
+ *  sell copies of the Software, and to permit persons to whom the Software is
+ *  furnished to do so, subject to the following conditions:
+ *
+ *  The above copyright notice and this permission notice shall be included in
+ *  all copies or substantial portions of the Software.
+ *
+ *  THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ *  IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ *  FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
+ *  THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ *  LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
+ *  FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
+ *  IN THE SOFTWARE.
+ *
+ *  Bit calculations adapted from https://github.com/adamvr/arduino-base64,
+ *  commit 999595783185a0afcba156d7276dfeaa9cb5382f.
+ */
+
+#ifndef CPPCODEC_DETAIL_BASE64
+#define CPPCODEC_DETAIL_BASE64
+
+#include <stdexcept>
+#include <stdint.h>
+
+#include "../data/access.hpp"
+#include "../parse_error.hpp"
+#include "config.hpp"
+#include "stream_codec.hpp"
+
+namespace cppcodec {
+namespace detail {
+
+template <typename CodecVariant>
+class base64 : public CodecVariant::template codec_impl<base64<CodecVariant>>
+{
+public:
+    static inline constexpr uint8_t binary_block_size() { return 3; }
+    static inline constexpr uint8_t encoded_block_size() { return 4; }
+
+    static CPPCODEC_ALWAYS_INLINE constexpr uint8_t num_encoded_tail_symbols(uint8_t num_bytes)
+    {
+        return (num_bytes == 1) ? 2    // 2 symbols, 2 padding characters
+                : (num_bytes == 2) ? 3 // 3 symbols, 1 padding character
+                : throw std::domain_error("invalid number of bytes in a tail block");
+    }
+
+    template <uint8_t I>
+    static CPPCODEC_ALWAYS_INLINE constexpr uint8_t index(
+            const uint8_t* b /*binary block*/) noexcept
+    {
+        static_assert(I >= 0 && I < encoded_block_size(),
+                "invalid encoding symbol index in a block");
+
+        return (I == 0) ? (b[0] >> 2) // first 6 bits
+                : (I == 1) ? (((b[0] & 0x3) << 4) | (b[1] >> 4))
+                : (I == 2) ? (((b[1] & 0xF) << 2) | (b[2] >> 6))
+                : /*I == 3*/ (b[2] & 0x3F); // last 6 bits
+    }
+
+    template <bool B>
+    using uint8_if = typename std::enable_if<B, uint8_t>::type;
+
+    template <uint8_t I>
+    static CPPCODEC_ALWAYS_INLINE constexpr uint8_if<I == 1 || I == 2> index_last(
+            const uint8_t* b /*binary block*/) noexcept
+    {
+        return (I == 1) ? ((b[0] & 0x3) << 4)     // abbreviated 2nd symbol
+                : /*I == 2*/ ((b[1] & 0xF) << 2); // abbreviated 3rd symbol
+    }
+
+    template <uint8_t I>
+    static CPPCODEC_ALWAYS_INLINE uint8_if<I != 1 && I != 2> index_last(
+            const uint8_t* /*binary block*/)
+    {
+        throw std::domain_error("invalid last encoding symbol index in a tail");
+    }
+
+    template <typename Result, typename ResultState>
+    static CPPCODEC_ALWAYS_INLINE void decode_block(
+            Result& decoded, ResultState&, const alphabet_index_t* idx);
+
+    template <typename Result, typename ResultState>
+    static CPPCODEC_ALWAYS_INLINE void decode_tail(
+            Result& decoded, ResultState&, const alphabet_index_t* idx, size_t idx_len);
+};
+
+
+template <typename CodecVariant>
+template <typename Result, typename ResultState>
+CPPCODEC_ALWAYS_INLINE void base64<CodecVariant>::decode_block(
+        Result& decoded, ResultState& state, const alphabet_index_t* idx)
+{
+    uint_fast32_t dec = (idx[0] << 18) | (idx[1] << 12) | (idx[2] << 6) | idx[3];
+    data::put(decoded, state, static_cast<uint8_t>(dec >> 16));
+    data::put(decoded, state, static_cast<uint8_t>((dec >> 8) & 0xFF));
+    data::put(decoded, state, static_cast<uint8_t>(dec & 0xFF));
+}
+
+template <typename CodecVariant>
+template <typename Result, typename ResultState>
+CPPCODEC_ALWAYS_INLINE void base64<CodecVariant>::decode_tail(
+        Result& decoded, ResultState& state, const alphabet_index_t* idx, size_t idx_len)
+{
+    if (idx_len == 1) {
+        throw invalid_input_length(
+                "invalid number of symbols in last base64 block: found 1, expected 2 or 3");
+    }
+
+    // idx_len == 2: decoded size 1
+    data::put(decoded, state, static_cast<uint8_t>((idx[0] << 2) + ((idx[1] & 0x30) >> 4)));
+    if (idx_len == 2) {
+        return;
+    }
+
+    // idx_len == 3: decoded size 2
+    data::put(decoded, state, static_cast<uint8_t>(((idx[1] & 0xF) << 4) + ((idx[2] & 0x3C) >> 2)));
+}
+
+} // namespace detail
+} // namespace cppcodec
+
+#endif // CPPCODEC_DETAIL_BASE64
diff --git a/external/cppcodec/detail/codec.hpp b/external/cppcodec/detail/codec.hpp
new file mode 100644
index 0000000..47d9802
--- /dev/null
+++ b/external/cppcodec/detail/codec.hpp
@@ -0,0 +1,327 @@
+/**
+ *  Copyright (C) 2015 Topology LP
+ *  All rights reserved.
+ *
+ *  Permission is hereby granted, free of charge, to any person obtaining a copy
+ *  of this software and associated documentation files (the "Software"), to
+ *  deal in the Software without restriction, including without limitation the
+ *  rights to use, copy, modify, merge, publish, distribute, sublicense, and/or
+ *  sell copies of the Software, and to permit persons to whom the Software is
+ *  furnished to do so, subject to the following conditions:
+ *
+ *  The above copyright notice and this permission notice shall be included in
+ *  all copies or substantial portions of the Software.
+ *
+ *  THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ *  IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ *  FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
+ *  THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ *  LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
+ *  FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
+ *  IN THE SOFTWARE.
+ */
+
+#ifndef CPPCODEC_DETAIL_CODEC
+#define CPPCODEC_DETAIL_CODEC
+
+#include <assert.h>
+#include <stdint.h>
+#include <string>
+#include <vector>
+
+#include "../data/access.hpp"
+#include "../data/raw_result_buffer.hpp"
+
+namespace cppcodec {
+namespace detail {
+
+// SFINAE: Templates sometimes beat sensible overloads - make sure we don't call the wrong one.
+template <typename T>
+struct non_numeric : std::enable_if<!std::is_arithmetic<T>::value> { };
+
+
+/**
+ * Public interface for all the codecs. For API documentation, see README.md.
+ */
+template <typename CodecImpl>
+class codec
+{
+public:
+    //
+    // Encoding
+
+    // Convenient version, returns an std::string.
+    static std::string encode(const uint8_t* binary, size_t binary_size);
+    static std::string encode(const char* binary, size_t binary_size);
+    // static std::string encode(const T& binary); -> provided by template below
+
+    // Convenient version with templated result type.
+    template <typename Result> static Result encode(const uint8_t* binary, size_t binary_size);
+    template <typename Result> static Result encode(const char* binary, size_t binary_size);
+    template <typename Result = std::string, typename T = std::vector<uint8_t>>
+    static Result encode(const T& binary);
+
+    // Reused result container version. Resizes encoded_result before writing to it.
+    template <typename Result>
+    static void encode(Result& encoded_result, const uint8_t* binary, size_t binary_size);
+    template <typename Result>
+    static void encode(Result& encoded_result, const char* binary, size_t binary_size);
+    template <typename Result, typename T, typename non_numeric<T>::type* = nullptr>
+    static void encode(Result& encoded_result, const T& binary);
+
+    // Raw pointer output, assumes pre-allocated memory with size > encoded_size(binary_size).
+    static size_t encode(
+            char* encoded_result, size_t encoded_buffer_size,
+            const uint8_t* binary, size_t binary_size) noexcept;
+    static size_t encode(
+            char* encoded_result, size_t encoded_buffer_size,
+            const char* binary, size_t binary_size) noexcept;
+    template<typename T>
+    static size_t encode(
+            char* encoded_result, size_t encoded_buffer_size,
+            const T& binary) noexcept;
+
+    // Calculate the exact length of the encoded string based on binary size.
+    static constexpr size_t encoded_size(size_t binary_size) noexcept;
+
+    //
+    // Decoding
+
+    // Convenient version, returns an std::vector<uint8_t>.
+    static std::vector<uint8_t> decode(const char* encoded, size_t encoded_size);
+    // static std::vector<uint8_t> decode(const T& encoded); -> provided by template below
+
+    // Convenient version with templated result type.
+    template <typename Result> static Result decode(const char* encoded, size_t encoded_size);
+    template <typename Result = std::vector<uint8_t>, typename T = std::string>
+    static Result decode(const T& encoded);
+
+    // Reused result container version. Resizes binary_result before writing to it.
+    template <typename Result>
+    static void decode(Result& binary_result, const char* encoded, size_t encoded_size);
+    template <typename Result, typename T, typename non_numeric<T>::type* = nullptr>
+    static void decode(Result& binary_result, const T& encoded);
+
+    // Raw pointer output, assumes pre-allocated memory with size > decoded_max_size(encoded_size).
+    static size_t decode(
+            uint8_t* binary_result, size_t binary_buffer_size,
+            const char* encoded, size_t encoded_size);
+    static size_t decode(
+            char* binary_result, size_t binary_buffer_size,
+            const char* encoded, size_t encoded_size);
+    template<typename T> static size_t decode(
+            uint8_t* binary_result, size_t binary_buffer_size, const T& encoded);
+    template<typename T> static size_t decode(
+            char* binary_result, size_t binary_buffer_size, const T& encoded);
+
+    // Calculate the maximum size of the decoded binary buffer based on the encoded string length.
+    static constexpr size_t decoded_max_size(size_t encoded_size) noexcept;
+};
+
+
+//
+// Inline definitions of the above functions, using CRTP to call into CodecImpl
+//
+
+//
+// Encoding
+
+template <typename CodecImpl>
+inline std::string codec<CodecImpl>::encode(const uint8_t* binary, size_t binary_size)
+{
+    return encode<std::string>(binary, binary_size);
+}
+
+template <typename CodecImpl>
+inline std::string codec<CodecImpl>::encode(const char* binary, size_t binary_size)
+{
+    return encode<std::string>(reinterpret_cast<const uint8_t*>(binary), binary_size);
+}
+
+template <typename CodecImpl>
+template <typename Result>
+inline Result codec<CodecImpl>::encode(const uint8_t* binary, size_t binary_size)
+{
+    Result encoded_result;
+    encode(encoded_result, binary, binary_size);
+    return encoded_result;
+}
+
+template <typename CodecImpl>
+template <typename Result>
+inline Result codec<CodecImpl>::encode(const char* binary, size_t binary_size)
+{
+    return encode<Result>(reinterpret_cast<const uint8_t*>(binary), binary_size);
+}
+
+template <typename CodecImpl>
+template <typename Result, typename T>
+inline Result codec<CodecImpl>::encode(const T& binary)
+{
+    return encode<Result>(data::uchar_data(binary), data::size(binary));
+}
+
+template <typename CodecImpl>
+template <typename Result>
+inline void codec<CodecImpl>::encode(
+    Result& encoded_result, const uint8_t* binary, size_t binary_size)
+{
+    // This overload is where we reserve buffer capacity and call into CodecImpl.
+    size_t encoded_buffer_size = encoded_size(binary_size);
+    auto state = data::create_state(encoded_result, data::specific_t());
+    data::init(encoded_result, state, encoded_buffer_size);
+
+    CodecImpl::encode(encoded_result, state, binary, binary_size);
+    data::finish(encoded_result, state);
+    assert(data::size(encoded_result) == encoded_buffer_size);
+}
+
+template <typename CodecImpl>
+template <typename Result>
+inline void codec<CodecImpl>::encode(
+    Result& encoded_result, const char* binary, size_t binary_size)
+{
+    encode(encoded_result, reinterpret_cast<const uint8_t*>(binary), binary_size);
+}
+
+template <typename CodecImpl>
+template <typename Result, typename T, typename non_numeric<T>::type*>
+inline void codec<CodecImpl>::encode(Result& encoded_result, const T& binary)
+{
+    encode(encoded_result, data::uchar_data(binary), data::size(binary));
+}
+
+template <typename CodecImpl>
+inline size_t codec<CodecImpl>::encode(
+        char* encoded_result, size_t encoded_buffer_size,
+        const uint8_t* binary, size_t binary_size) noexcept
+{
+    // This overload is where we wrap the result pointer & size.
+    data::raw_result_buffer encoded(encoded_result, encoded_buffer_size);
+    encode(encoded, binary, binary_size);
+
+    size_t encoded_size = data::size(encoded);
+    if (encoded_size < encoded_buffer_size) {
+        encoded_result[encoded_size] = '\0';
+    }
+    return encoded_size;
+}
+
+template <typename CodecImpl>
+inline size_t codec<CodecImpl>::encode(
+        char* encoded_result, size_t encoded_buffer_size,
+        const char* binary, size_t binary_size) noexcept
+{
+    // This overload is where we wrap the result pointer & size.
+    return encode(encoded_result, encoded_buffer_size,
+            reinterpret_cast<const uint8_t*>(binary), binary_size);
+}
+
+template <typename CodecImpl>
+template <typename T>
+inline size_t codec<CodecImpl>::encode(
+        char* encoded_result, size_t encoded_buffer_size,
+        const T& binary) noexcept
+{
+    return encode(encoded_result, encoded_buffer_size, data::uchar_data(binary), data::size(binary));
+}
+
+template <typename CodecImpl>
+inline constexpr size_t codec<CodecImpl>::encoded_size(size_t binary_size) noexcept
+{
+    return CodecImpl::encoded_size(binary_size);
+}
+
+
+//
+// Decoding
+
+template <typename CodecImpl>
+inline std::vector<uint8_t> codec<CodecImpl>::decode(const char* encoded, size_t encoded_size)
+{
+    return decode<std::vector<uint8_t>>(encoded, encoded_size);
+}
+
+template <typename CodecImpl>
+template <typename Result>
+inline Result codec<CodecImpl>::decode(const char* encoded, size_t encoded_size)
+{
+    Result result;
+    decode(result, encoded, encoded_size);
+    return result;
+}
+
+template <typename CodecImpl>
+template <typename Result, typename T>
+inline Result codec<CodecImpl>::decode(const T& encoded)
+{
+    return decode<Result>(data::char_data(encoded), data::size(encoded));
+}
+
+template <typename CodecImpl>
+template <typename Result>
+inline void codec<CodecImpl>::decode(Result& binary_result, const char* encoded, size_t encoded_size)
+{
+    // This overload is where we reserve buffer capacity and call into CodecImpl.
+    size_t binary_buffer_size = decoded_max_size(encoded_size);
+    auto state = data::create_state(binary_result, data::specific_t());
+    data::init(binary_result, state, binary_buffer_size);
+
+    CodecImpl::decode(binary_result, state, encoded, encoded_size);
+    data::finish(binary_result, state);
+    assert(data::size(binary_result) <= binary_buffer_size);
+}
+
+
+template <typename CodecImpl>
+template <typename Result, typename T, typename non_numeric<T>::type*>
+inline void codec<CodecImpl>::decode(Result& binary_result, const T& encoded)
+{
+    decode(binary_result, data::char_data(encoded), data::size(encoded));
+}
+
+template <typename CodecImpl>
+inline size_t codec<CodecImpl>::decode(
+        uint8_t* binary_result, size_t binary_buffer_size,
+        const char* encoded, size_t encoded_size)
+{
+    return decode(reinterpret_cast<char*>(binary_result), binary_buffer_size, encoded, encoded_size);
+}
+
+template <typename CodecImpl>
+inline size_t codec<CodecImpl>::decode(
+        char* binary_result, size_t binary_buffer_size,
+        const char* encoded, size_t encoded_size)
+{
+    // This overload is where we wrap the result pointer & size.
+    data::raw_result_buffer binary(binary_result, binary_buffer_size);
+    decode(binary, encoded, encoded_size);
+    return data::size(binary);
+}
+
+template <typename CodecImpl>
+template <typename T>
+inline size_t codec<CodecImpl>::decode(
+        uint8_t* binary_result, size_t binary_buffer_size, const T& encoded)
+{
+    return decode(reinterpret_cast<char*>(binary_result), binary_buffer_size, encoded);
+}
+
+template <typename CodecImpl>
+template <typename T>
+inline size_t codec<CodecImpl>::decode(char* binary_result, size_t binary_buffer_size, const T& encoded)
+{
+    return decode(binary_result, binary_buffer_size, data::char_data(encoded), data::size(encoded));
+}
+
+template <typename CodecImpl>
+inline constexpr size_t codec<CodecImpl>::decoded_max_size(size_t encoded_size) noexcept
+{
+    return CodecImpl::decoded_max_size(encoded_size);
+}
+
+
+} // namespace detail
+} // namespace cppcodec
+
+#endif
diff --git a/external/cppcodec/detail/config.hpp b/external/cppcodec/detail/config.hpp
new file mode 100644
index 0000000..dc66f8f
--- /dev/null
+++ b/external/cppcodec/detail/config.hpp
@@ -0,0 +1,40 @@
+/**
+ *  Copyright (C) 2015 Topology LP
+ *  All rights reserved.
+ *
+ *  Permission is hereby granted, free of charge, to any person obtaining a copy
+ *  of this software and associated documentation files (the "Software"), to
+ *  deal in the Software without restriction, including without limitation the
+ *  rights to use, copy, modify, merge, publish, distribute, sublicense, and/or
+ *  sell copies of the Software, and to permit persons to whom the Software is
+ *  furnished to do so, subject to the following conditions:
+ *
+ *  The above copyright notice and this permission notice shall be included in
+ *  all copies or substantial portions of the Software.
+ *
+ *  THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ *  IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ *  FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
+ *  THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ *  LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
+ *  FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
+ *  IN THE SOFTWARE.
+ */
+
+#ifndef CPPCODEC_DETAIL_CONFIG_HPP
+#define CPPCODEC_DETAIL_CONFIG_HPP
+
+#ifndef __has_attribute
+  #define __has_attribute(x) 0
+#endif
+
+#if __GNUC__ || __has_attribute(always_inline)
+#define CPPCODEC_ALWAYS_INLINE inline __attribute__((always_inline))
+#elif defined(_MSC_VER) && !defined(__INTEL_COMPILER)
+#define CPPCODEC_ALWAYS_INLINE inline __forceinline
+#else
+#define CPPCODEC_ALWAYS_INLINE inline
+#endif
+
+#endif // CPPCODEC_DETAIL_CONFIG_HPP
+
diff --git a/external/cppcodec/detail/stream_codec.hpp b/external/cppcodec/detail/stream_codec.hpp
new file mode 100644
index 0000000..d4204bc
--- /dev/null
+++ b/external/cppcodec/detail/stream_codec.hpp
@@ -0,0 +1,439 @@
+/**
+ *  Copyright (C) 2015 Topology LP
+ *  Copyright (C) 2018 Jakob Petsovits
+ *  All rights reserved.
+ *
+ *  Permission is hereby granted, free of charge, to any person obtaining a copy
+ *  of this software and associated documentation files (the "Software"), to
+ *  deal in the Software without restriction, including without limitation the
+ *  rights to use, copy, modify, merge, publish, distribute, sublicense, and/or
+ *  sell copies of the Software, and to permit persons to whom the Software is
+ *  furnished to do so, subject to the following conditions:
+ *
+ *  The above copyright notice and this permission notice shall be included in
+ *  all copies or substantial portions of the Software.
+ *
+ *  THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ *  IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ *  FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
+ *  THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ *  LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
+ *  FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
+ *  IN THE SOFTWARE.
+ */
+
+#ifndef CPPCODEC_DETAIL_STREAM_CODEC
+#define CPPCODEC_DETAIL_STREAM_CODEC
+
+#include <limits>
+#include <stdlib.h> // for abort()
+#include <stdint.h>
+
+#include "../parse_error.hpp"
+#include "config.hpp"
+
+namespace cppcodec {
+namespace detail {
+
+using alphabet_index_t = uint_fast16_t;
+
+template <typename Codec, typename CodecVariant>
+class stream_codec
+{
+public:
+    template <typename Result, typename ResultState> static void encode(
+            Result& encoded_result, ResultState&, const uint8_t* binary, size_t binary_size);
+
+    template <typename Result, typename ResultState> static void decode(
+            Result& binary_result, ResultState&, const char* encoded, size_t encoded_size);
+
+    static constexpr size_t encoded_size(size_t binary_size) noexcept;
+    static constexpr size_t decoded_max_size(size_t encoded_size) noexcept;
+};
+
+template <bool GeneratesPadding> // default for CodecVariant::generates_padding() == false
+struct padder {
+    template <typename CodecVariant, typename Result, typename ResultState, typename EncodedBlockSizeT>
+    CPPCODEC_ALWAYS_INLINE void operator()(Result&, ResultState&, EncodedBlockSizeT) { }
+};
+
+template<> // specialization for CodecVariant::generates_padding() == true
+struct padder<true> {
+    template <typename CodecVariant, typename Result, typename ResultState, typename EncodedBlockSizeT>
+    CPPCODEC_ALWAYS_INLINE void operator()(
+            Result& encoded, ResultState& state, EncodedBlockSizeT num_padding_characters)
+    {
+        for (EncodedBlockSizeT i = 0; i < num_padding_characters; ++i) {
+            data::put(encoded, state, CodecVariant::padding_symbol());
+        }
+    }
+};
+
+template <size_t I>
+struct enc {
+    // Block encoding: Go from 0 to (block size - 1), append a symbol for each iteration unconditionally.
+    template <typename Codec, typename CodecVariant, typename Result, typename ResultState>
+    static CPPCODEC_ALWAYS_INLINE void block(Result& encoded, ResultState& state, const uint8_t* src)
+    {
+        using EncodedBlockSizeT = decltype(Codec::encoded_block_size());
+        constexpr static const EncodedBlockSizeT SymbolIndex = static_cast<EncodedBlockSizeT>(I - 1);
+
+        enc<I - 1>().template block<Codec, CodecVariant>(encoded, state, src);
+        data::put(encoded, state, CodecVariant::symbol(Codec::template index<SymbolIndex>(src)));
+    }
+
+    // Tail encoding: Go from 0 until (runtime) num_symbols, append a symbol for each iteration.
+    template <typename Codec, typename CodecVariant, typename Result, typename ResultState,
+            typename EncodedBlockSizeT = decltype(Codec::encoded_block_size())>
+    static CPPCODEC_ALWAYS_INLINE void tail(
+            Result& encoded, ResultState& state, const uint8_t* src, EncodedBlockSizeT num_symbols)
+    {
+        constexpr static const EncodedBlockSizeT SymbolIndex = Codec::encoded_block_size() - I;
+        constexpr static const EncodedBlockSizeT NumSymbols = SymbolIndex + static_cast<EncodedBlockSizeT>(1);
+
+        if (num_symbols == NumSymbols) {
+            data::put(encoded, state, CodecVariant::symbol(Codec::template index_last<SymbolIndex>(src)));
+            padder<CodecVariant::generates_padding()> pad;
+#ifdef _MSC_VER
+            pad.operator()<CodecVariant>(encoded, state, Codec::encoded_block_size() - NumSymbols);
+#else
+            pad.template operator()<CodecVariant>(encoded, state, Codec::encoded_block_size() - NumSymbols);
+#endif
+            return;
+        }
+        data::put(encoded, state, CodecVariant::symbol(Codec::template index<SymbolIndex>(src)));
+        enc<I - 1>().template tail<Codec, CodecVariant>(encoded, state, src, num_symbols);
+    }
+};
+
+template<> // terminating specialization
+struct enc<0> {
+    template <typename Codec, typename CodecVariant, typename Result, typename ResultState>
+    static CPPCODEC_ALWAYS_INLINE void block(Result&, ResultState&, const uint8_t*) { }
+
+    template <typename Codec, typename CodecVariant, typename Result, typename ResultState,
+            typename EncodedBlockSizeT = decltype(Codec::encoded_block_size())>
+    static CPPCODEC_ALWAYS_INLINE void tail(Result&, ResultState&, const uint8_t*, EncodedBlockSizeT)
+    {
+        abort(); // Not reached: block() should be called if num_symbols == block size, not tail().
+    }
+};
+
+template <typename Codec, typename CodecVariant>
+template <typename Result, typename ResultState>
+inline void stream_codec<Codec, CodecVariant>::encode(
+        Result& encoded_result, ResultState& state,
+        const uint8_t* src, size_t src_size)
+{
+    using encoder = enc<Codec::encoded_block_size()>;
+
+    const uint8_t* src_end = src + src_size;
+
+    if (src_size >= Codec::binary_block_size()) {
+        src_end -= Codec::binary_block_size();
+
+        for (; src <= src_end; src += Codec::binary_block_size()) {
+            encoder::template block<Codec, CodecVariant>(encoded_result, state, src);
+        }
+        src_end += Codec::binary_block_size();
+    }
+
+    if (src_end > src) {
+        auto remaining_src_len = src_end - src;
+        if (!remaining_src_len || remaining_src_len >= Codec::binary_block_size()) {
+            abort();
+            return;
+        }
+        auto num_symbols = Codec::num_encoded_tail_symbols(static_cast<uint8_t>(remaining_src_len));
+        encoder::template tail<Codec, CodecVariant>(encoded_result, state, src, num_symbols);
+    }
+}
+
+// Range & lookup table generation, see
+// http://stackoverflow.com/questions/13313980/populate-an-array-using-constexpr-at-compile-time
+// and http://cplusadd.blogspot.ca/2013/02/c11-compile-time-lookup-tablearray-with.html
+
+template<unsigned... Is> struct seq {};
+
+template<unsigned N, unsigned... Is>
+struct gen_seq : gen_seq<N - 4, N - 4, N - 3, N - 2, N - 1, Is...> {
+    // Clang up to 3.6 has a limit of 256 for template recursion,
+    // so pass a few more symbols at once to make it work.
+    static_assert(N % 4 == 0, "I must be divisible by 4 to eventually end at 0");
+};
+template<unsigned... Is>
+struct gen_seq<0, Is...> : seq<Is...> {};
+
+template <size_t N>
+struct lookup_table_t {
+    alphabet_index_t lookup[N];
+    static constexpr size_t size = N;
+};
+
+template<typename LambdaType, unsigned... Is>
+constexpr lookup_table_t<sizeof...(Is)> make_lookup_table(seq<Is...>, LambdaType value_for_index) {
+    return { { value_for_index(Is)... } };
+}
+
+template<unsigned N, typename LambdaType>
+constexpr lookup_table_t<N> make_lookup_table(LambdaType evalFunc) {
+    return make_lookup_table(gen_seq<N>(), evalFunc);
+}
+
+// CodecVariant::symbol() provides a symbol for an index.
+// Use recursive templates to get the inverse lookup table for fast decoding.
+
+template <typename T>
+static CPPCODEC_ALWAYS_INLINE constexpr size_t num_possible_values()
+{
+    return static_cast<size_t>(
+            static_cast<intmax_t>(std::numeric_limits<T>::max())
+                    - static_cast<intmax_t>(std::numeric_limits<T>::min()) + 1);
+}
+
+template <typename CodecVariant, alphabet_index_t InvalidIdx, size_t I>
+struct index_if_in_alphabet {
+    static CPPCODEC_ALWAYS_INLINE constexpr alphabet_index_t for_symbol(char symbol)
+    {
+        return (CodecVariant::symbol(
+                    static_cast<alphabet_index_t>(CodecVariant::alphabet_size() - I)) == symbol)
+            ? static_cast<alphabet_index_t>(CodecVariant::alphabet_size() - I)
+            : index_if_in_alphabet<CodecVariant, InvalidIdx, I - 1>::for_symbol(symbol);
+    }
+};
+template <typename CodecVariant, alphabet_index_t InvalidIdx>
+struct index_if_in_alphabet<CodecVariant, InvalidIdx, 0> { // terminating specialization
+    static CPPCODEC_ALWAYS_INLINE constexpr alphabet_index_t for_symbol(char)
+    {
+        return InvalidIdx;
+    }
+};
+
+template <typename CodecVariant, size_t I>
+struct padding_searcher {
+    static CPPCODEC_ALWAYS_INLINE constexpr bool exists_padding_symbol()
+    {
+        // Clang up to 3.6 has a limit of 256 for template recursion,
+        // so pass a few more symbols at once to make it work.
+        static_assert(I % 4 == 0, "I must be divisible by 4 to eventually end at 0");
+
+        return CodecVariant::is_padding_symbol(
+                        static_cast<char>(num_possible_values<char>() - I - 4))
+                || CodecVariant::is_padding_symbol(
+                        static_cast<char>(num_possible_values<char>() - I - 3))
+                || CodecVariant::is_padding_symbol(
+                        static_cast<char>(num_possible_values<char>() - I - 2))
+                || CodecVariant::is_padding_symbol(
+                        static_cast<char>(num_possible_values<char>() - I - 1))
+                || padding_searcher<CodecVariant, I - 4>::exists_padding_symbol();
+    }
+};
+template <typename CodecVariant>
+struct padding_searcher<CodecVariant, 0> { // terminating specialization
+    static CPPCODEC_ALWAYS_INLINE constexpr bool exists_padding_symbol() { return false; }
+};
+
+template <typename CodecVariant>
+struct alphabet_index_info
+{
+    static constexpr const size_t num_possible_symbols = num_possible_values<char>();
+
+    static constexpr const alphabet_index_t padding_idx = 1 << 8;
+    static constexpr const alphabet_index_t invalid_idx = 1 << 9;
+    static constexpr const alphabet_index_t eof_idx = 1 << 10;
+    static constexpr const alphabet_index_t stop_character_mask = static_cast<alphabet_index_t>(~0xFFu);
+
+    static constexpr const bool padding_allowed = padding_searcher<
+            CodecVariant, num_possible_symbols>::exists_padding_symbol();
+
+    static CPPCODEC_ALWAYS_INLINE constexpr bool allows_padding()
+    {
+        return padding_allowed;
+    }
+    static CPPCODEC_ALWAYS_INLINE constexpr bool is_padding(alphabet_index_t idx)
+    {
+        return allows_padding() ? (idx == padding_idx) : false;
+    }
+    static CPPCODEC_ALWAYS_INLINE constexpr bool is_invalid(alphabet_index_t idx) { return idx == invalid_idx; }
+    static CPPCODEC_ALWAYS_INLINE constexpr bool is_eof(alphabet_index_t idx) { return idx == eof_idx; }
+    static CPPCODEC_ALWAYS_INLINE constexpr bool is_stop_character(alphabet_index_t idx)
+    {
+        return (idx & stop_character_mask) != 0;
+    }
+
+private:
+    static CPPCODEC_ALWAYS_INLINE constexpr
+    alphabet_index_t valid_index_or(alphabet_index_t a, alphabet_index_t b)
+    {
+        return a == invalid_idx ? b : a;
+    }
+
+    using idx_if_in_alphabet = index_if_in_alphabet<
+            CodecVariant, invalid_idx, CodecVariant::alphabet_size()>;
+
+    static CPPCODEC_ALWAYS_INLINE constexpr alphabet_index_t index_of(char symbol)
+    {
+        return valid_index_or(idx_if_in_alphabet::for_symbol(symbol),
+            CodecVariant::is_eof_symbol(symbol) ? eof_idx
+            : CodecVariant::is_padding_symbol(symbol) ? padding_idx
+            : invalid_idx);
+    }
+
+    // GCC <= 4.9 has a bug with retaining constexpr when passing a function pointer.
+    // To get around this, we'll create a callable with operator() and pass that one.
+    // Unfortunately, MSVC prior to VS 2017 (for MinSizeRel or Release builds)
+    // chokes on this by compiling the project in 20 minutes instead of seconds.
+    // So let's define two separate variants and remove the old GCC one whenever we
+    // decide not to support GCC < 5.0 anymore.
+#if defined(__GNUC__) && !defined(__clang__) && __GNUC__ < 5
+    struct index_at {
+        CPPCODEC_ALWAYS_INLINE constexpr alphabet_index_t operator()(size_t symbol) const {
+            return index_of(CodecVariant::normalized_symbol(static_cast<char>(symbol)));
+        }
+    };
+#else
+    static CPPCODEC_ALWAYS_INLINE constexpr alphabet_index_t index_at(size_t symbol)
+    {
+        return index_of(CodecVariant::normalized_symbol(static_cast<char>(symbol)));
+    }
+#endif
+
+public:
+    struct lookup {
+        static CPPCODEC_ALWAYS_INLINE alphabet_index_t for_symbol(char symbol)
+        {
+#if defined(__GNUC__) && !defined(__clang__) && __GNUC__ < 5
+            static constexpr const auto t = make_lookup_table<num_possible_symbols>(index_at());
+#else
+            static constexpr const auto t = make_lookup_table<num_possible_symbols>(&index_at);
+#endif
+            static_assert(t.size == num_possible_symbols,
+                    "lookup table must cover each possible (character) symbol");
+            return t.lookup[static_cast<uint8_t>(symbol)];
+        }
+    };
+};
+
+//
+// At long last! The actual decode/encode functions.
+
+template <typename Codec, typename CodecVariant>
+template <typename Result, typename ResultState>
+inline void stream_codec<Codec, CodecVariant>::decode(
+        Result& binary_result, ResultState& state,
+        const char* src_encoded, size_t src_size)
+{
+    using alphabet_index_lookup = typename alphabet_index_info<CodecVariant>::lookup;
+    const char* src = src_encoded;
+    const char* src_end = src + src_size;
+
+    alphabet_index_t alphabet_indexes[Codec::encoded_block_size()] = {};
+    alphabet_indexes[0] = alphabet_index_info<CodecVariant>::eof_idx;
+
+    alphabet_index_t* const alphabet_index_start = &alphabet_indexes[0];
+    alphabet_index_t* const alphabet_index_end = &alphabet_indexes[Codec::encoded_block_size()];
+    alphabet_index_t* alphabet_index_ptr = &alphabet_indexes[0];
+
+    while (src < src_end) {
+        if (CodecVariant::should_ignore(*src)) {
+            ++src;
+            continue;
+        }
+        *alphabet_index_ptr = alphabet_index_lookup::for_symbol(*src);
+        if (alphabet_index_info<CodecVariant>::is_stop_character(*alphabet_index_ptr)) {
+            break;
+        }
+        ++src;
+        ++alphabet_index_ptr;
+
+        if (alphabet_index_ptr == alphabet_index_end) {
+            Codec::decode_block(binary_result, state, alphabet_indexes);
+            alphabet_index_ptr = alphabet_index_start;
+        }
+    }
+
+    if (alphabet_index_info<CodecVariant>::is_invalid(*alphabet_index_ptr)) {
+        throw symbol_error(*src);
+    }
+    ++src;
+
+    alphabet_index_t* last_index_ptr = alphabet_index_ptr;
+    if (alphabet_index_info<CodecVariant>::is_padding(*last_index_ptr)) {
+        if (last_index_ptr == alphabet_index_start) {
+            // Don't accept padding at the start of a block.
+            // The encoder should have omitted that padding altogether.
+            throw padding_error();
+        }
+        // We're in here because we just read a (first) padding character. Try to read more.
+        // Count with last_index_ptr, but store in alphabet_index_ptr so we don't
+        // overflow the array in case the input data is too long.
+        ++last_index_ptr;
+        while (src < src_end) {
+            *alphabet_index_ptr = alphabet_index_lookup::for_symbol(*(src++));
+
+            if (alphabet_index_info<CodecVariant>::is_eof(*alphabet_index_ptr)) {
+                *alphabet_index_ptr = alphabet_index_info<CodecVariant>::padding_idx;
+                break;
+            }
+            if (!alphabet_index_info<CodecVariant>::is_padding(*alphabet_index_ptr)) {
+                throw padding_error();
+            }
+
+            ++last_index_ptr;
+            if (last_index_ptr > alphabet_index_end) {
+                throw padding_error();
+            }
+        }
+    }
+
+    if (last_index_ptr != alphabet_index_start)  {
+        if ((CodecVariant::requires_padding()
+                    || alphabet_index_info<CodecVariant>::is_padding(*alphabet_index_ptr)
+                    ) && last_index_ptr != alphabet_index_end)
+        {
+            // If the input is not a multiple of the block size then the input is incorrect.
+            throw padding_error();
+        }
+        if (alphabet_index_ptr >= alphabet_index_end) {
+            abort();
+            return;
+        }
+        Codec::decode_tail(binary_result, state, alphabet_indexes,
+                static_cast<size_t>(alphabet_index_ptr - alphabet_index_start));
+    }
+}
+
+template <typename Codec, typename CodecVariant>
+inline constexpr size_t stream_codec<Codec, CodecVariant>::encoded_size(size_t binary_size) noexcept
+{
+    using C = Codec;
+
+    // constexpr rules make this a lot harder to read than it actually is.
+    return CodecVariant::generates_padding()
+            // With padding, the encoded size is a multiple of the encoded block size.
+            // To calculate that, round the binary size up to multiple of the binary block size,
+            // then convert to encoded by multiplying with { base32: 8/5, base64: 4/3 }.
+            ? (binary_size + (C::binary_block_size() - 1)
+                    - ((binary_size + (C::binary_block_size() - 1)) % C::binary_block_size()))
+                    * C::encoded_block_size() / C::binary_block_size()
+            // No padding: only pad to the next multiple of 5 bits, i.e. at most a single extra byte.
+            : (binary_size * C::encoded_block_size() / C::binary_block_size())
+                    + (((binary_size * C::encoded_block_size()) % C::binary_block_size()) ? 1 : 0);
+}
+
+template <typename Codec, typename CodecVariant>
+inline constexpr size_t stream_codec<Codec, CodecVariant>::decoded_max_size(size_t encoded_size) noexcept
+{
+    using C = Codec;
+
+    return CodecVariant::requires_padding()
+            ? (encoded_size / C::encoded_block_size() * C::binary_block_size())
+            : (encoded_size / C::encoded_block_size() * C::binary_block_size())
+                    + ((encoded_size % C::encoded_block_size())
+                            * C::binary_block_size() / C::encoded_block_size());
+}
+
+} // namespace detail
+} // namespace cppcodec
+
+#endif // CPPCODEC_DETAIL_STREAM_CODEC