format_context.hpp

#pragma once
 
#include "fly/types/string/concepts.hpp"
#include "fly/types/string/detail/format_parameters.hpp"
#include "fly/types/string/formatters.hpp"
 
#include <cstddef>
#include <type_traits>
 
namespace fly::detail {
 
template <typename OutputIterator, fly::StandardCharacter CharType>
class BasicFormatContext
{
    using FormatParameter = BasicFormatParameter<BasicFormatContext>;
 
public:
    using char_type = CharType;
 
    template <typename T>
    using formatter_type = fly::Formatter<std::remove_cvref_t<T>, CharType>;
 
    template <typename... Parameters>
    constexpr BasicFormatContext(
        OutputIterator out,
        const BasicFormatParameters<BasicFormatContext, Parameters...> &parameters) noexcept;
 
    FormatParameter arg(std::size_t index) const;
 
    OutputIterator &out();
 
private:
    BasicFormatContext(const BasicFormatContext &) = delete;
    BasicFormatContext &operator=(const BasicFormatContext &) = delete;
 
    OutputIterator m_out;
 
    const FormatParameter *m_parameters;
    const std::size_t m_parameters_size;
};
 
//==================================================================================================
template <typename OutputIterator, fly::StandardCharacter CharType>
template <typename... Parameters>
constexpr BasicFormatContext<OutputIterator, CharType>::BasicFormatContext(
    OutputIterator out,
    const BasicFormatParameters<BasicFormatContext, Parameters...> &parameters) noexcept :
    m_out(std::move(out)),
    m_parameters(parameters.m_parameters.data()),
    m_parameters_size(parameters.m_parameters.size())
{
}
 
//==================================================================================================
template <typename OutputIterator, fly::StandardCharacter CharType>
inline auto BasicFormatContext<OutputIterator, CharType>::arg(std::size_t index) const
    -> FormatParameter
{
    if (index < m_parameters_size)
    {
        return m_parameters[index];
    }
 
    return {};
}
 
//==================================================================================================
template <typename OutputIterator, fly::StandardCharacter CharType>
inline OutputIterator &BasicFormatContext<OutputIterator, CharType>::out()
{
    return m_out;
}
 
} // namespace fly::detail