std::moneypunct::curr_symbol, do_curr_symbol

From cppreference.com
< cpplrm; | localelrm; | moneypunct
Defined in header <locale>
public:
string_type curr_symbol() const;
(1)
protected:
virtual string_type do_curr_symbol() const;
(2)
1) Public member function, calls the member function do_curr_symbol of the most derived class.
2) Returns the string used as the currency identifier by this locale. If International (the second template parameter of std::moneypunct) is false, the identifier is usually a single (wide) character, such as "" or "$". If International is true, the identifier is usually a four-character string holding the three-character ISO 4217 currency code followed by a space ("JPY " or "USD ")

Return value

The object of type string_type holding the currency symbol or code.

Example

#include <iostream>
#include <locale>
void show_ccy(const char* locname)
{
    std::locale loc(locname);
    std::cout << locname << " currency symbol is "
              << std::use_facet<std::moneypunct<char, true>>(loc).curr_symbol()
              << "or " << std::use_facet<std::moneypunct<char>>(loc).curr_symbol()
              << " for short\n";
}
int main()
{
    show_ccy("en_US.utf8");
    show_ccy("ja_JP.utf8");
    show_ccy("sv_SE.utf8");
    show_ccy("ru_RU.utf8");
    show_ccy("vi_VN.utf8");
}

Output:

en_US.utf8 currency symbol is USD or $ for short
ja_JP.utf8 currency symbol is JPY or  for short
sv_SE.utf8 currency symbol is SEK or kr for short
ru_RU.utf8 currency symbol is RUB or руб for short
vi_VN.utf8 currency symbol is VND or  for short

See also

provides the formatting pattern for currency values
(virtual protected member function)