std::moneypunct::pos_format, do_pos_format, neg_format, do_neg_format

From cppreference.com
< cpplrm; | localelrm; | moneypunct
Defined in header <locale>
public:
pattern pos_format() const;
(1)
public:
pattern neg_format() const;
(2)
protected:
virtual pattern do_pos_format() const;
(3)
protected:
virtual pattern do_neg_format() const;
(4)
1) Public member function, calls the member function do_pos_format of the most derived class.
2) Public member function, calls the member function do_neg_format of the most derived class.
3) Returns the format structure (of type std::money_base::format) which describes the formatting of positive monetary values.
4) Returns the format structure (of type std::money_base::format) which describes the formatting of negative monetary values.

The standard specializations of std::moneypunct return the pattern {symbol, sign, none, value}

Return value

The object of type std::money_base::format describing the formatting used by this locale.

Notes

While std::money_put uses pos_format for formatting positive values and neg_format for formatting negative values, std::money_get uses neg_format for parsing all monetary values: it assumes that neg_format is compatible with pos_format.

Example

#include <locale>
#include <iostream>
#include <iomanip>

struct my_punct : std::moneypunct_byname<char, false> {
    my_punct(const char* name) : moneypunct_byname(name) {}
    pattern do_pos_format() const { return { {value, space, symbol, sign} };}
    pattern do_neg_format() const { return { {value, space, symbol, sign} };}
};
int main()
{
    std::cout.imbue(std::locale("en_US.utf8"));
    std::cout << "american locale: " << std::showbase
              << std::put_money(12345678.0) << '\n';

    std::cout.imbue(std::locale(std::cout.getloc(), new my_punct("en_US.utf8")));
    std::cout << "locale with modified moneypunct:\n"
              << std::put_money(12345678.0)  << '\n'
              << std::put_money(-12345678.0) << '\n';
}

Output:

american locale: $123,456.78
locale with modified moneypunct:
123,456.78 $
123,456.78 $-

See also

provides the string to use as the currency identifier
(virtual protected member function)
provides the string to indicate a positive or negative value
(virtual protected member function)
[virtual]
parses a monetary value from an input stream
(virtual protected member function of std::money_get)
[virtual]
formats a monetary value and writes to output stream
(virtual protected member function of std::money_put)