Namespaces
Variants

std::moneypunct<CharT,International>:: decimal_point, do_decimal_point

From cppreference.net
C++
Text processing library
Localization library
std::moneypunct
Defined in header <locale>
public :
CharT decimal_point ( ) const ;
(1)
protected :
virtual CharT do_decimal_point ( ) const ;
(2)
1) Public member function, calls the member function do_decimal_point of the most derived class.
2) Returns the character to use as the decimal point separator in monetary I/O if the format uses fractions (that is, if do_frac_digits() is greater than zero). For typical U.S. locales, it is the character '.' (or L '.' ).

Return value

The object of type CharT holding the decimal point character.

Example

Run this code 
#include <iomanip>
#include <iostream>
#include <locale>
void show_dpt(const char* locname)
{
    std::locale loc(locname);
    std::cout.imbue(loc);
    std::cout << locname << " decimal point is '"
              << std::use_facet<std::moneypunct<char>>(loc).decimal_point()
              << "' for example: " << std::showbase << std::put_money(123);
    if (std::use_facet<std::moneypunct<char>>(loc).frac_digits() == 0)
        std::cout << " (does not use frac digits)";
    std::cout << '\n';
}
int main()
{
    show_dpt("en_US.utf8");
    show_dpt("ja_JP.utf8");
    show_dpt("sv_SE.utf8");
    show_dpt("de_DE.utf8");
}

Output: 

en_US.utf8 decimal point is '.' for example: $1.23
ja_JP.utf8 decimal point is '.' for example: ￥123 (does not use frac digits)
sv_SE.utf8 decimal point is ',' for example: 1,23 kr
de_DE.utf8 decimal point is ',' for example: 1,23 €

See also

[virtual]
provides the number of digits to display after the decimal point
(virtual protected member function)