Boost
C++ Libraries
...one of the most highly
regarded and expertly designed C++ library projects in the
world.
— Herb Sutter and Andrei
Alexandrescu, C++
Coding Standards
Boost
C++ Libraries
...one of the most highly
regarded and expertly designed C++ library projects in the
world.
— Herb Sutter and Andrei
Alexandrescu, C++
Coding Standards
| Front Page / Data Types / Concepts / Integral Constant |
An Integral Constant is a holder class for a compile-time value of an integral type. Every Integral Constant is also a nullary Metafunction, returning itself. An integral constant object is implicitly convertible to the corresponding run-time value of the wrapped integral type.
In the following table and subsequent specifications, n is a model of Integral Constant.
| Expression | Type | Complexity |
|---|---|---|
| n::tag | integral_c_tag | Constant time. |
| n::value_type | An integral type | Constant time. |
| n::value | An integral constant expression | Constant time. |
| n::type | Integral Constant | Constant time. |
| next<n>::type | Integral Constant | Constant time. |
| prior<n>::type | Integral Constant | Constant time. |
| n::value_type const c = n() | Constant time. |
| Expression | Semantics |
|---|---|
| n::tag | n's tag type; n::tag::value is n's conversion rank. |
| n::value_type | A cv-unqualified type of n::value. |
| n::value | The value of the wrapped integral constant. |
| n::type | is_same<n::type,n>::value == true. |
| next<n>::type | An Integral Constant c of type n::value_type such that c::value == n::value + 1. |
| prior<n>::type | An Integral Constant c of type n::value_type such that c::value == n::value - 1. |
| n::value_type const c = n() | c == n::value. |