<locale>

<locale> provides locale-aware facets for character classification, collation, number/currency formatting, and time display. Most code avoids it in favor of simpler, more portable alternatives.

If you need to handle locale-specific collation or formatting in a GUI application, this is where to look; otherwise keep everything in the C locale or use explicit format strings.

This example checks the current locale name and demonstrates switching to the C locale for output formatting.

// compile: g++ -std=c++11 -o localeexample localeexample.cpp
// run: ./localeexample
// description: check locale and use a facet
 
#include <locale>
#include <iostream>
 
int main() {
    std::locale loc;
    std::cout << "name: " << loc.name() << "\n";
 
    std::cout.imbue(std::locale("C"));
    std::cout << "3.14 in C locale: " << 3.14 << "\n";
 
    return 0;
}