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#include <iostream>
template<char...cs> struct compile_time_string
{static constexpr char str[sizeof...(cs)+1] = {cs...,'\0'};};
template<char...cs>
const char compile_time_string<cs...>::str[sizeof...(cs)+1];
template<char...cs> struct compile_time_stringbuilder
{typedef compile_time_string<cs...> string;};
//remove leading spaces from stringbuilder
template<char...cs> struct compile_time_stringbuilder<' ', cs...>
{typedef typename compile_time_stringbuilder<cs...>::string string;};
template<char...cs, class...Ts>
compile_time_stringbuilder<cs...,'\n'> concatenate_compile_time_format_string(compile_time_stringbuilder<cs...>);
template<char...cs, class...Ts>
auto concatenate_compile_time_format_string(compile_time_stringbuilder<cs...>,int,Ts...args)
-> decltype(concatenate_compile_time_format_string(compile_time_stringbuilder<cs...,' ','%','d'>(),args...));
template<char...cs, class...Ts>
auto concatenate_compile_time_format_string(compile_time_stringbuilder<cs...>,const char*,Ts...args)
-> decltype(concatenate_compile_time_format_string(compile_time_stringbuilder<cs...,' ','%','s'>(),args...));
template<char...cs, class...Ts>
auto concatenate_compile_time_format_string(compile_time_stringbuilder<cs...>,double,Ts...args)
-> decltype(concatenate_compile_time_format_string(compile_time_stringbuilder<cs...,' ','%','f'>(),args...));
template<class...Ts>
constexpr const char* build_compile_time_format_string()
{
using compile_time_stringbuilder = decltype(concatenate_compile_time_format_string(compile_time_stringbuilder<>(),std::declval<Ts>()...));
using compile_time_string = typename compile_time_stringbuilder::string;
return compile_time_string::str;
}
template<typename T, class...Args>
XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX
clang++ -O2 -Wall -pedantic -pthread -std=c++11 -fms-extensions main.cpp && ./a.out

%d %s %f