| Regina 7.0 Calculation Engine
    | 
A struct that holds either a single value of type T or nothing at all, depending on whether the given compile-time condition holds. More...
#include <utilities/typeutils.h>
| Public Attributes | |
| T | value { defaultValue } | 
| The data member to store if condition is true.  More... | |
A struct that holds either a single value of type T or nothing at all, depending on whether the given compile-time condition holds.
If condition is true, then this struct holds a single data member value of type T, which will be initialised on construction with defaultValue.
The advantage to using this class over std::conditional is that it supports assigning a default value on construction.
| condition | trueif the data member should be included, orfalseif this struct should be empty. | 
| T | the data type to store. | 
| defaultValue | the value to assign the data member upon construction. | 
| T regina::EnableIf< condition, T, defaultValue >::value { defaultValue } | 
The data member to store if condition is true.