// # pair
//
// Particular case of tuple for two elements (TODO inheritance based?).
//
// Methods which also exist for tuple will not be discussed.
//
// Specially important because of `map`, for which find() for example
// returns key value tuples.
#include "common.hpp"
template
std::pair my_make_pair(T1 t1, T2 t2) {
return std::pair(t1, t2);
}
int main() {
// Access: can also be done via `.first` and `.second` in addition to tuple `get`..
{
std::pair p(0, "");
assert(std::get<0>(p) == p.first);
assert(std::get<1>(p) == p.second);
}
// # make_pair
//
// Saves re-typing the types on the constructor.
//
// http://stackoverflow.com/questions/9270563/what-is-the-purpose-of-stdmake-pair-vs-the-constructor-of-stdpair/41521422#41521422
{
auto p = my_make_pair(1, std::string("one"));
assert(p.first == 1);
assert(p.second == "one");
p = std::make_pair(1, "asdf");
}
// # Relational operators
//
// Lexicographical.
//
// http://stackoverflow.com/questions/2819245/is-stdpairint-stdstring-ordering-well-defined
{
assert(std::make_pair(1, 1) == std::make_pair(1, 1));
assert(std::make_pair(1, 2) < std::make_pair(2, 1));
assert(std::make_pair(2, 1) > std::make_pair(1, 2));
}
}