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lnxsurf

Member

Registered: 2014-05-28

Posts: 68

[SOLVED] C++ operator== with shared_ptr and glm::vec3

Hello I have a problem to compile the following code. It seems to me strange why the compiler does not accept my code:

bool operator==(const std::shared_ptr<glm::vec3> &v0, const glm::vec3 v1) {
	return *v0 == v1;
}

bool operator==(const glm::vec3 v0, const std::shared_ptr<glm::vec3> &v1) {
	return v0 == *v1;
}

TEST (smartPointersAndOperators, OperatorEquals2) {
	std::vector<std::shared_ptr<glm::vec3>> allAs {
		std::make_shared<glm::vec3>(),
		std::make_shared<glm::vec3>(),
		std::make_shared<glm::vec3>()};
	glm::vec3 obj;
	auto it = std::find(allAs.cbegin(), allAs.cend(), obj);
}

The compile error is

n file included from /home/program/test/C++11/c++11_Features_main.cpp:8:
In file included from /usr/include/gtest/gtest.h:55:
In file included from /usr/bin/../lib/gcc/x86_64-linux-gnu/5.4.0/../../../../include/c++/5.4.0/ostream:38:
In file included from /usr/bin/../lib/gcc/x86_64-linux-gnu/5.4.0/../../../../include/c++/5.4.0/ios:40:
In file included from /usr/bin/../lib/gcc/x86_64-linux-gnu/5.4.0/../../../../include/c++/5.4.0/bits/char_traits.h:39:
In file included from /usr/bin/../lib/gcc/x86_64-linux-gnu/5.4.0/../../../../include/c++/5.4.0/bits/stl_algobase.h:71:
/usr/bin/../lib/gcc/x86_64-linux-gnu/5.4.0/../../../../include/c++/5.4.0/bits/predefined_ops.h:194:17: error: invalid operands to binary expression ('const std::shared_ptr<glm::tvec3<float,
      glm::precision::packed_highp> >' and 'const glm::tvec3<float, glm::precision::packed_highp>')
        { return *__it == _M_value; }
                 ~~~~~ ^  ~~~~~~~~
/usr/bin/../lib/gcc/x86_64-linux-gnu/5.4.0/../../../../include/c++/5.4.0/bits/stl_algo.h:120:8: note: in instantiation of function template specialization
      '__gnu_cxx::__ops::_Iter_equals_val<const glm::tvec3<float, glm::precision::packed_highp> >::operator()<__gnu_cxx::__normal_iterator<const std::shared_ptr<glm::tvec3<float,
      glm::precision::packed_highp> > *, std::vector<std::shared_ptr<glm::tvec3<float, glm::precision::packed_highp> >, std::allocator<std::shared_ptr<glm::tvec3<float,
      glm::precision::packed_highp> > > > > >' requested here
          if (__pred(__first))
              ^
/usr/bin/../lib/gcc/x86_64-linux-gnu/5.4.0/../../../../include/c++/5.4.0/bits/stl_algo.h:161:14: note: in instantiation of function template specialization
      'std::__find_if<__gnu_cxx::__normal_iterator<const std::shared_ptr<glm::tvec3<float, glm::precision::packed_highp> > *, std::vector<std::shared_ptr<glm::tvec3<float,
      glm::precision::packed_highp> >, std::allocator<std::shared_ptr<glm::tvec3<float, glm::precision::packed_highp> > > > >, __gnu_cxx::__ops::_Iter_equals_val<const glm::tvec3<float,
      glm::precision::packed_highp> > >' requested here
      return __find_if(__first, __last, __pred,
             ^
/usr/bin/../lib/gcc/x86_64-linux-gnu/5.4.0/../../../../include/c++/5.4.0/bits/stl_algo.h:3790:19: note: in instantiation of function template specialization
      'std::__find_if<__gnu_cxx::__normal_iterator<const std::shared_ptr<glm::tvec3<float, glm::precision::packed_highp> > *, std::vector<std::shared_ptr<glm::tvec3<float,
      glm::precision::packed_highp> >, std::allocator<std::shared_ptr<glm::tvec3<float, glm::precision::packed_highp> > > > >, __gnu_cxx::__ops::_Iter_equals_val<const glm::tvec3<float,
      glm::precision::packed_highp> > >' requested here
      return std::__find_if(__first, __last,
                  ^

Please, I need help...

Last edited by lnxsurf (2017-03-08 17:43:00)

Xyne

Administrator/PM

Registered: 2008-08-03

Posts: 6,963

Website

Re: [SOLVED] C++ operator== with shared_ptr and glm::vec3

Next time, please post a minimal example with headers and a main function for others to test your code. Posting error messages without the matching code and line numbers just makes it harder for others to help.

Searching for "std::find" and "no match for ‘operator==’" quickly turns up a relevant Stack Overflow thread: http://stackoverflow.com/questions/7287 … y-operator

Related:
http://www.cplusplus.com/reference/algorithm/find_if/
http://en.cppreference.com/w/cpp/language/extending_std

Working example using find_if:

#include <iostream>
#include <vector>
#include <memory>
#include <algorithm>
#include <glm/glm.hpp>

// http://stackoverflow.com/questions/7287224/why-isnt-stdfind-using-my-operator
// http://www.cplusplus.com/reference/algorithm/find_if/
// http://en.cppreference.com/w/cpp/language/extending_std

using namespace std;

bool
operator ==(
  const std::shared_ptr<glm::vec3> &v0,
  const glm::vec3 v1
)
{
  return *v0 == v1;
}



bool
operator ==(
  const glm::vec3 v0,
  const std::shared_ptr<glm::vec3> &v1
)
{
  return v0 == *v1;
}



struct VecFinder
{
  VecFinder(const glm::vec3 & obj) : o(obj) {}
  const glm::vec3 o;
  bool operator()(const std::shared_ptr<glm::vec3> & lhs) const { return *lhs == o; }
};



int
main() {
  glm::vec3 obj {0};
  std::vector<std::shared_ptr<glm::vec3>> allAs {
    std::make_shared<glm::vec3>(),
    std::make_shared<glm::vec3>(obj),
    std::make_shared<glm::vec3>()
  };
  auto it = std::find_if(allAs.cbegin(), allAs.cend(), VecFinder(obj));
  std::cout << ((*it == obj) ? "found it" : "found nothing") << std::endl;
}

---

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lnxsurf

Member

Registered: 2014-05-28

Posts: 68

Re: [SOLVED] C++ operator== with shared_ptr and glm::vec3

Thanks a lot.