std::make_pair vs C++11 uniform initializer
Is there a drawback to using the latter? Is std::make_pair
more v开发者_StackOverflow中文版ersatile/compatible or are they truly interchangeable?
Thanks!
How are they related? Using an initializer list constructor doesn't work for a pair, because a pair
is heterogeneously typed, while an initializer list constructor uses an initializer_list<T>
, which is only usable to retrieve an homogeneously typed initializer list.
(Looking into the spec, it should really be called "initializer-list constructor", instead of "initializer list constructor". Do you really mean to refer to the first? If not, what do you refer to?).
If you just refer to initialize a std::pair<>
using an initializer list against using std::make_pair
and using auto
, I think both are fine.
auto p = std::make_pair(a, b);
std::pair<A, B> p{a, b};
If you have already the types A
and B
and can use them for the pair
, then the initializer list is a good way to use. If you haven't, then make_pair
might be a good thing. If you have types A
and B
, but aren't sure whether they are already transformed properly (i.e they should not be array or function types, and you probably also want them to be non-reference types), then it might be easier to use std::make_pair
, which will properly decay the type of the expressions.
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