std::ratio

From Cppreference

Defined in header `<ratio>`

template< intmax_t Num, intmax_t Denom = 1 > class ratio { public: static const num = /* see below /; static const dem = / see below */; }		(C++11 feature)

The class template ratio is the core class in the compile-time rational arithmetic library. It reduces the supplied numerator and denominator to the lowest terms.

Several convenience SI typedefs are already provided:


typedef std::ratio<1, 1000000000000000000000000> yocto; //see below typedef std::ratio<1, 1000000000000000000000> zepto; //see below typedef std::ratio<1, 1000000000000000000> atto; typedef std::ratio<1, 1000000000000000> femto; typedef std::ratio<1, 1000000000000> pico; typedef std::ratio<1, 1000000000> nano; typedef std::ratio<1, 1000000> micro; typedef std::ratio<1, 1000> milli; typedef std::ratio<1, 100> centi; typedef std::ratio<1, 10> deci; typedef std::ratio<10, 1> deca; typedef std::ratio<100, 1> hecto; typedef std::ratio<1000, 1> kilo; typedef std::ratio<1000000, 1> mega; typedef std::ratio<1000000000, 1> giga; typedef std::ratio<1000000000000, 1> tera; typedef std::ratio<1000000000000000, 1> peta; typedef std::ratio<1000000000000000000, 1> exa; typedef std::ratio<1000000000000000000000, 1> zetta; //see below typedef std::ratio<1000000000000000000000000, 1> yotta; //see below		(C++11 feature)

The typedefs yocto, zepto, zetta, yotta are provided only if intmax_t is sufficient to represent the values used to instantiate the templates.

[edit] Template parameters

`Nom`	-	defines the numerator of the ratio
`Denom`	-	defines the denominator of the ratio. It cannot be equal to 0

[edit] Member objects


`num`	defines the reduced numerator (public static member constant)

`den`	defines the reduced denominator (public static member constant)