#include <iostream>
#include <string_view>
#include <source_location>
/*
若想查看源代码对应的信息,之前都是使用log类,或宏__FILE__, __LINE__等,C++20中新增source_location类,可以更友好的展示文件名称、行号、列号、函数名称
*/
void log(const std::string_view message,
const std::source_location location =
std::source_location::current())
{
std::cout << "file: "
<< location.file_name() << "("
<< location.line() << ":"
<< location.column() << ") `"
<< location.function_name() << "`: "
<< message << '\n';
}
template <typename T> void fun(T x)
{
log(x);
}
int main(int, char*[])
{
log("Hello world!");
fun("Hello C++20!");
}