auto Function with if Statement won't return a value

Question

I made a template and an auto function that compare 2 values and return the smallest one. This is my code:

#include 

        

Answer 1

Until yesterday (2017-12-06) this was not compiling under MSVC. But after VS 15.5 update it does.

    auto msvc_does_compile = [](auto _string)
     {
      using string_type = decltype(_string);
      return std::vector{};
     };
   /*
    OK since VS 2017 15.5 update
   auto vec1 = msvc_does_compile( std::string{} );
   */

Adding explicit return type will choke MSVC , but not gcc/clang as usual:

auto msvc_does_not_compile = [](auto _string)
    // explicit return type makes msvc not to compile
    -> std::vector< decltype(_string) >
  {
    using string_type = decltype(_string);
    return std::vector{};
  };

And something of the same but simpler will be stopped even at the IDE stage:

    auto msvc_ide_does_not_allow = []( bool wide )
    {
       if (wide)
        return std::vector();

        return std::vector();
    };

Yes, again that troublesome pair gcc/clang has no problems with the above. Try which ever online ide you prefer to convince yourself...