mirror of
https://github.com/nlohmann/json.git
synced 2024-12-27 07:37:51 +08:00
124 lines
3.0 KiB
C++
124 lines
3.0 KiB
C++
#pragma once
|
|
|
|
#include <algorithm> // copy
|
|
#include <cstddef> // size_t
|
|
#include <ios> // streamsize
|
|
#include <iterator> // back_inserter
|
|
#include <memory> // shared_ptr, make_shared
|
|
#include <ostream> // basic_ostream
|
|
#include <string> // basic_string
|
|
#include <vector> // vector
|
|
#include <nlohmann/detail/macro_scope.hpp>
|
|
|
|
namespace nlohmann
|
|
{
|
|
namespace detail
|
|
{
|
|
/// abstract output adapter interface
|
|
template<typename CharType> struct output_adapter_protocol
|
|
{
|
|
virtual void write_character(CharType c) = 0;
|
|
virtual void write_characters(const CharType* s, std::size_t length) = 0;
|
|
virtual ~output_adapter_protocol() = default;
|
|
};
|
|
|
|
/// a type to simplify interfaces
|
|
template<typename CharType>
|
|
using output_adapter_t = std::shared_ptr<output_adapter_protocol<CharType>>;
|
|
|
|
/// output adapter for byte vectors
|
|
template<typename CharType>
|
|
class output_vector_adapter : public output_adapter_protocol<CharType>
|
|
{
|
|
public:
|
|
explicit output_vector_adapter(std::vector<CharType>& vec) noexcept
|
|
: v(vec)
|
|
{}
|
|
|
|
void write_character(CharType c) override
|
|
{
|
|
v.push_back(c);
|
|
}
|
|
|
|
JSON_HEDLEY_NON_NULL(2)
|
|
void write_characters(const CharType* s, std::size_t length) override
|
|
{
|
|
std::copy(s, s + length, std::back_inserter(v));
|
|
}
|
|
|
|
private:
|
|
std::vector<CharType>& v;
|
|
};
|
|
|
|
/// output adapter for output streams
|
|
template<typename CharType>
|
|
class output_stream_adapter : public output_adapter_protocol<CharType>
|
|
{
|
|
public:
|
|
explicit output_stream_adapter(std::basic_ostream<CharType>& s) noexcept
|
|
: stream(s)
|
|
{}
|
|
|
|
void write_character(CharType c) override
|
|
{
|
|
stream.put(c);
|
|
}
|
|
|
|
JSON_HEDLEY_NON_NULL(2)
|
|
void write_characters(const CharType* s, std::size_t length) override
|
|
{
|
|
stream.write(s, static_cast<std::streamsize>(length));
|
|
}
|
|
|
|
private:
|
|
std::basic_ostream<CharType>& stream;
|
|
};
|
|
|
|
/// output adapter for basic_string
|
|
template<typename CharType, typename StringType = std::basic_string<CharType>>
|
|
class output_string_adapter : public output_adapter_protocol<CharType>
|
|
{
|
|
public:
|
|
explicit output_string_adapter(StringType& s) noexcept
|
|
: str(s)
|
|
{}
|
|
|
|
void write_character(CharType c) override
|
|
{
|
|
str.push_back(c);
|
|
}
|
|
|
|
JSON_HEDLEY_NON_NULL(2)
|
|
void write_characters(const CharType* s, std::size_t length) override
|
|
{
|
|
str.append(s, length);
|
|
}
|
|
|
|
private:
|
|
StringType& str;
|
|
};
|
|
|
|
template<typename CharType, typename StringType = std::basic_string<CharType>>
|
|
class output_adapter
|
|
{
|
|
public:
|
|
output_adapter(std::vector<CharType>& vec)
|
|
: oa(std::make_shared<output_vector_adapter<CharType>>(vec)) {}
|
|
|
|
output_adapter(std::basic_ostream<CharType>& s)
|
|
: oa(std::make_shared<output_stream_adapter<CharType>>(s)) {}
|
|
|
|
output_adapter(StringType& s)
|
|
: oa(std::make_shared<output_string_adapter<CharType, StringType>>(s)) {}
|
|
|
|
operator output_adapter_t<CharType>()
|
|
{
|
|
return oa;
|
|
}
|
|
|
|
private:
|
|
output_adapter_t<CharType> oa = nullptr;
|
|
};
|
|
} // namespace detail
|
|
} // namespace nlohmann
|