Incorrect use of move

[ColinH]

Incorrect use of move

[ColinH]

it would have been handled by the registry<Comps...>::add(apx::entity entity, const Comp& component) overload?

Unfortunately (?) not, it chooses the other overload. It can be slightly annoying because the overload resolution between const foo& and foo&& behaves differently depending on whether foo is a template parameter or not, so one also has to be extra careful when refactoring code and transforming back or forth between a function and a function template...

colin@magic:/tmp/ramdisk> cat t.cpp 
#include <string>
#include <iostream>

struct foo
{
   template< typename T >
   int bar( T&& )
   {
      std::cerr << "+++" << std::endl;
      std::cerr << __PRETTY_FUNCTION__ << std::endl;
      return 1;
   }

   template< typename T >
   int bar( const T& )
   {
      std::cerr << "---" << std::endl;
      std::cerr << __PRETTY_FUNCTION__ << std::endl;
      return 2;
   }
};

int main()
{
   foo f;
   std::string a;
   const std::string b;
   return f.bar( a ) + f.bar( std::move( a ) ) + f.bar( b );
}
colin@magic:/tmp/ramdisk> clang++ -Wall -Wextra -O3 -pedantic -std=c++17 t.cpp 
colin@magic:/tmp/ramdisk> ./a.out 
+++
int foo::bar(T &&) [T = std::__1::basic_string<char> &]
+++
int foo::bar(T &&) [T = std::__1::basic_string<char>]
---
int foo::bar(const T &) [T = std::__1::basic_string<char>]

[fullptr]

I suspect I may have gotten away with this, since if I passed a some_component_type& it would have been handled by the registry<Comps...>::add(apx::entity entity, const Comp& component) overload? Nevertheless this is a very nice simplification.

[fullptr]

Ahh I see, that example makes it very clear, thanks!