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std::numpunct<CharT>::thousands_sep, do_thousands_sep

Defined in header <locale> 
public:
char_type thousands_sep() const;
 (1) 
protected:
virtual char_type do_thousands_sep() const;
 (2)
1) Public member function, calls the member function do_thousands_sep of the most derived class.
2) Returns the character to be used as the separator between digit groups when parsing or formatting integers and integral parts of floating-point values.

Return value

The object of type char_type to use as the thousands separator. The standard specializations of std::numpunct return ',' and L','.

Example

#include <iostream>
#include <locale>
 
struct space_out : std::numpunct<char>
{
    char do_thousands_sep()   const { return ' '; }  // separate with spaces
    std::string do_grouping() const { return "\1"; } // groups of 1 digit
};
 
int main()
{
    std::cout << "default locale: " << 12345678 << '\n';
    std::cout.imbue(std::locale(std::cout.getloc(), new space_out));
    std::cout << "locale with modified numpunct: " << 12345678 << '\n';
}

Output:

default locale: 12345678
locale with modified numpunct: 1 2 3 4 5 6 7 8

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 20 C++98 the return type was string_type changed to char_type

See also

[virtual]
 provides the numbers of digits between each pair of thousands separators
(virtual protected member function)

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