std::ratio_subtract

template <class R1, class R2> ratio_subtract;

Subtract ratios

This class template alias generates a ratio type that is the difference between the ratio types R1 and R2.

The resulting type is the same as if ratio_subtract was defined as:

1
2

template <typename R1, typename R2>
using ratio_subtract = std::ratio < R1::num*R2::den-R2::num*R1::den, R1::den*R2::den >;

A program shall not cause any expression in the above definition to expand to values not representable as an intmax_t.

Template parameters

R1,R2: ratio types to be subtracted.

Member constants

The same as ratio (ratio_subtract is merely a template alias).

member constexpr	description
`num`	Numerator
`den`	Denominator

The values of num and den represent the result of the subtraction operation.

Member types

The same as ratio (ratio_subtract is merely a template alias).

member type	definition	description
`type`	`ratio<num,den>`	The ratio type with the result of the subtraction.

Example

// ratio_subtract example
#include <iostream>
#include <ratio>

int main ()
{
  typedef std::ratio<2,3> two_thirds;
  typedef std::ratio<1,2> one_half;

  typedef std::ratio_subtract<two_thirds,one_half> diff;

  std::cout << "diff = " << diff::num << "/" << diff::den;
  std::cout << " (which is: " << ( double(diff::num) / diff::den ) << ")" << std::endl;

  return 0;
}

Output:

diff = 1/6 (which is: 0.166667)

std::ratio_subtract

Template parameters

Member constants

Member types

Example

See also