fmt_cxx20.md

Usage of {fmt} vs C++20

1. streams.hpp -- string_view, format_arg_store / format_args, format_context
2. streams.cpp -- string_view, format_args, memory_buffer, vformat_to()
3. diagnostic.cpp -- format()
4. string.cpp -- format_args::format_arg, format_args, format_context, detail::make_arg, vformat()

{fmt}	C++20
fmt::format()	std::format()
fmt::vformat()	std::vformat()
fmt::vformat_to()	std::vformat_to()
detail::make_arg()	std::make_format_args()?
format_arg_store	Unspecified, but it exists
format_args::format_arg	std::basic_format_arg
format_args	std::basic_format_args
format_context	std::basic_format_context
memory_buffer	See below
string_view	std::string_view

std::vector<char> buf;
std::format_to(std::back_inserter(buf), "{}", 42);
// buf contains "42"