simple sprintf wrapper

version 0

#include <memory>
#include <string>
#include <stdexcept>
template<typename ... Args>
std::string string_format( const std::string& format, Args ... args )
{
int size_s = std::snprintf( nullptr, 0, format.c_str(), args ... ) + 1; // Extra space for '\0'
if( size_s <= 0 ){ throw std::runtime_error( "Error during formatting." ); }
auto size = static_cast<size_t>( size_s );
std::unique_ptr<char[]> buf( new char[ size ] );
std::snprintf( buf.get(), size, format.c_str(), args ... );
return std::string( buf.get(), buf.get() + size - 1 ); // We don't want the '\0' inside
}
int main()
{
stringg aa = format("test %d %s", 100, "abc");
printf(aa.c_str());
return 0;
}

version 1

#include <stdio.h>
#include <stdarg.h>
void Error (char * format, ...)
{
char buffer[256];
va_list args;
va_start (args, format);
vsnprintf (buffer, 255, format, args);
//do something with the error
va_end (args);
}

ref

cplusplus.com/reference/cstdio/vsnprintf/: https://cplusplus.com/reference/cstdio/vsnprintf/
cplusplus.com/reference/cstdio/snprintf/: https://cplusplus.com/reference/cstdio/snprintf/
c++ - std::string formatting like sprintf - Stack Overflow: https://stackoverflow.com/questions/2342162/stdstring-formatting-like-sprintf
c++ - How to pass variable number of arguments to printf/sprintf - Stack Overflow: https://stackoverflow.com/questions/1056411/how-to-pass-variable-number-of-arguments-to-printf-sprintf
Variadic functions - cppreference.com: https://en.cppreference.com/w/c/variadic

posted on   yusisc  阅读(3)  评论(0编辑  收藏  举报

相关博文:
阅读排行:
· 阿里最新开源QwQ-32B,效果媲美deepseek-r1满血版,部署成本又又又降低了!
· 开源Multi-agent AI智能体框架aevatar.ai,欢迎大家贡献代码
· Manus重磅发布:全球首款通用AI代理技术深度解析与实战指南
· 被坑几百块钱后,我竟然真的恢复了删除的微信聊天记录!
· AI技术革命,工作效率10个最佳AI工具

导航

< 2025年3月 >
23 24 25 26 27 28 1
2 3 4 5 6 7 8
9 10 11 12 13 14 15
16 17 18 19 20 21 22
23 24 25 26 27 28 29
30 31 1 2 3 4 5
点击右上角即可分享
微信分享提示