CODEWITHSUNDEEP
c++functionparameter-passingauto
DevInd
DevInd

Reputation: 1785

auto as function argument

In C++14 something like this was made legal (for lambdas) :-

auto l = [](auto x, auto y) { return x+y; };

However something like this is still not legal :-

auto sum (auto x, auto y)
{
     return x+y;
}

My curiosity is why wasn't the second one added to the standard (though it is supposed to be added in C++17 hopefully) ? What were the pros & cons of the second one ?

Upvotes: 5

Views: 253

Answers (2)

Sorin
Sorin

Reputation: 11968

It's part of a TS that wasn't ready in time for C++14.

It is going to be equivalent to 

template <typename T, typename U>
auto sum(T x, U y) { return x+y }

The only pro is that it's slightly shorter. Everything else is the same.

Upvotes: 3

Lightness Races in Orbit
Lightness Races in Orbit

Reputation: 385405

It wasn't added because it's another thing to add and time is not infinite. We cannot expect all useful enhancements to be added in one go, can we? As you have identified, it will be in C++17.

Upvotes: 6

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