header

<ratio>

Ratio header
This header declares the ratio class template and several auxiliary types to operate with them.

A ratio expresses a proportion (such as 1:3, or 1000:1) as a set of two compile-time constants (its numerator and its denominator). The type itself is used to express the ratio (objects of these types hold no value).

Within the standard library, ratio types are used as template parameters for duration objects (see chrono header).

Classes

ratio
Ratio (class template )

ratio arithmetic:

ratio_add
Add two ratios (class template )
ratio_subtract
Subtract ratios (class template )
ratio_multiply
Multiply two ratios (class template )
ratio_divide
Divide ratios (class template )

ratio comparison:

ratio_equal
Compare ratios (class template )
ratio_not_equal
Compare ratios for inequality (class template )
ratio_less
Compare ratios for less-than inequality (class template )
ratio_less_equal
Compare ratios for equality or less-than inequality (class template )
ratio_greater
Compare ratios for greater than inequality (class template )
ratio_greater_equal
Compare ratios for equality or greater-than inequality (class template )