std::money_get

Class template std::money_get encapsulates the rules for parsing monetary values from character streams. The standard I/O manipulator std::get_money uses the std::money_get facet of the I/O stream's locale.

cpp/locale/locale/facet

std-money get-inheritance.svg

Inheritance diagram

If a std::money_get specialization is not guaranteed to be provided by the standard library (see below), the behaviors of its get() and do_get() are not guaranteed as specified.

#include <iomanip>
#include <iostream>
#include <iterator>
#include <locale>
#include <sstream>
 
int main()
{
 std::string str = "1ドル.11 2ドル.22 3ドル.33";
 std::cout << std::fixed << std::setprecision (2);
 
 std::cout << '\"' << str << "\" parsed with the I/O manipulator: ";
 std::istringstream s1(str);
 s1.imbue(std::locale ("en_US.UTF-8"));
 
 long double val;
 while (s1 >> std::get_money (val))
 std::cout << val / 100 << ' ';
 std::cout << '\n';
 
 str = "USD 1,234.56";
 std::cout << '\"' << str << "\" parsed with the facet directly: ";
 std::istringstream s2(str);
 s2.imbue(std::locale ("en_US.UTF-8"));
 
 auto& f = std::use_facet <std::money_get<char>>(s2.getloc());
 std::ios_base::iostate err;
 std::istreambuf_iterator <char> beg(s2), end;
 f.get(beg, end, true, s2, err, val);
 
 std::cout << val / 100 << '\n';
}

Output:

"1ドル.11 2ドル.22 3ドル.33" parsed with the I/O manipulator: 1.11 2.22 3.33
"USD 1,234.56" parsed with the facet directly: 1234.56

[edit] Defect reports

The following behavior-changing defect reports were applied retroactively to previously published C++ standards.

DR	Applied to	Behavior as published	Correct behavior
LWG 427	C++98	`money_get` was guaranteed to accept any `CharT` that meets the requirements for a character on which any of the iostream components can be instantiated	only guarantees to accept char, wchar_t and other implementation- defined character types
LWG 2392	C++98	only character type `CharT` could be guaranteed to be accepted by `money_get`	can guarantee to accept implementation- defined character container types