...one of the most highly
regarded and expertly designed C++ library projects in the
world.
— Herb Sutter and Andrei
Alexandrescu, C++
Coding Standards
The TR1
Tuple interface is specified to provide uniform access to std::pair
as if it were a 2 element tuple.
tuple_size<std::pair<T1, T2> >::value
Type: An MPL Integral Constant
Value: Returns 2, the number of elements in a pair.
tuple_element<0, std::pair<T1, T2> >::type
Type: T1
Value: Returns the type of the first element of the pair
tuple_element<1, std::pair<T1, T2> >::type
Type: T2
Value: Returns thetype of the second element of the pair
template<int I, typename T1, typename T2> P& get(std::pair<T1, T2>& pr); template<int I, typename T1, typename T2> const P& get(const std::pair<T1, T2>& pr);
Type: If I
== 0
P
is T1
,
else if I ==
1
P
is T2
else the program is
ill-formed.
[*Returns: pr.first
if I
== 0
else pr.second
.