c++ - Efficient way to refer to the type-name of the iterator without typing the entire container definition? -

c++ - Efficient way to refer to the type-name of the iterator without typing the entire container definition? -

is there more efficient way refer typename of container's iterator typing

std::unordered_map<keyclass, valueclass>::iterator

every time need iterator?

of course, there is

typedef boost::unordered_map<keyclass, valueclass>::iterator classitr

but introducing typedef's every container not strike me readable code. beingness new c++, , assuming 1 has reference container want utilize - there along lines of

container<keyclass, valueclass> x; x::iterator_type

or other obvious shortcut missing?

this 1 of reasons why c++11 introduced new meaning of auto keyword:

auto = vec.begin();

the compiler work out type of it initializer in similar manner template type deduction.

pre-c++11, usual approach utilize typedefs have suggested. can useful typedef container , give relative that:

typedef std::unordered_map<key, value> map; map m; map::iterator = m.begin();

you can give more meaningful name typedef describes kind of map is. example, if had map names phone numbers, phone call phone_map , iterator phone_map::iterator.

auto useful tool perfect forwarding

c++ boost containers boost-iterators