GLID subclassing

glid.hpp

#pragma once
#include <GL/glew.h>

namespace gldr {

// Safe-moving non-copyable OpenGL id wrapper

template<typename Deleter>
class GLId { 
    Deleter deleter;
    GLuint innerId;

    // =delete commented out due to MSVS support
    GLId(GLId const&) /* = delete*/;
    GLId& operator=(GLId const&) /* = delete*/;

    // doesn't work in msvs god knows why
   /* template<typename Deleter_t>
    static auto call_deleter(Deleter_t& del, GLuint handle) -> decltype(del(handle)) {
        return del(handle);
    }

    template<typename Deleter_t>
    static auto call_deleter(Deleter_t& del, GLuint handle) -> decltype(del(1, &handle)) {
        return del(1, &handle);
    }*/

public:
    operator GLuint () const { return innerId; }

    // meant to be used with glGenXs and glDeleteXs functions
    const GLuint* const get_ptr() const { return &innerId; }
    GLuint* get_ptr() { return &innerId; }

    GLId(Deleter del) 
        : innerId(0)
        , deleter(std::move(del))
    { }
    
    GLId(GLuint id, Deleter del)
        : innerId(id)
        , deleter(std::move(del))
    { }

    GLId(GLId&& other) {
        innerId = other.innerId;
        other.innerId = 0;
    }

    GLId& operator= (GLId&& other) {
        innerId = other.innerId;
        other.innerId = 0;
        return *this;
    }

    GLId& operator= (GLuint id) {
        innerId = id;
        return *this;
    }

    ~GLId() {
        //call_deleter(deleter, innerId);
        deleter(innerId);
    }

    bool operator== (GLuint b) {
        return innerId == b;
    }
    bool operator!= (GLuint b) {
        return !((*this) == b);
    }

    bool operator== (GLId<Deleter> const& b) {
        return innerId == b.innerId;
    }
    bool operator!= (GLId<Deleter> const& b) {
        return !((*this) == b);
    }
};

}

// SUBCLASS
namespace {
    GLuint vboCreate () { 
        GLuint id = 0;
        glGenFramebuffers(1, &id);
        if (!id)
            throw std::runtime_error("Problem creating a texture");
        return id;
    }

    void vboDelete(GLuint id) {
        glDeleteFramebuffers(1, &id);
    }

    class VboGLId : public GLId<decltype(&vboDelete)> {
        VboGLId(const VboGLId& other) /* = delete */;
    public:
        VboGLId(VboGLId&& other) 
            : GLId((GLId<decltype(&vboDelete)(other))) {
        }
        VboGLId()
            : GLId(vboCreate(), vboDelete)
        { }
        VboGLId(GLuint id)
            : GLId(id, vboDelete)
        { }
    };
}