template <class Rep, class Period = ratio<1> > class duration;
| type | Representation | Period | 
|---|---|---|
| hours | signed integral type of at least 23 bits | ratio<3600,1> | 
| minutes | signed integral type of at least 29 bits | ratio<60,1> | 
| seconds | signed integral type of at least 35 bits | ratio<1,1> | 
| milliseconds | signed integral type of at least 45 bits | ratio<1,1000> | 
| microseconds | signed integral type of at least 55 bits | ratio<1,1000000> | 
| nanoseconds | signed integral type of at least 64 bits | ratio<1,1000000000> | 
| member type | definition | notes | 
|---|---|---|
| rep | The first template parameter (Rep) | Representation type used as the type for the internal count object. | 
| period | The second template parameter (Period) | The ratio type that represents a period in seconds. |