pointer_test.h

#pragma once
 
#include <vector>
 
namespace cgv {
namespace utils {
 
/* This class provides methods to test if a stored pointer points to addresses of given variables or inside the range of object instances. */
class pointer_test {
private:
    bool one_of() const {
        return false;
    }
 
public:
    const void* ptr = nullptr;
 
    pointer_test(const void* ptr) : ptr(ptr) {}
 
    bool is(const void* ptr) const {
        return this->ptr == ptr;
    }
 
    template<typename T>
    bool is(const T& ref) const {
        return is(static_cast<const void*>(&ref));
    }
 
    template <typename T, typename... Ts>
    bool one_of(const T& ref, const Ts&... refs) const {
 
        /* C++ 17
        if constexpr(sizeof...(refs))
            return is(ref) || one_of(refs...);
        else
            return is(ref);
        */
 
        return is(ref) || one_of(refs...);
    }
 
    bool one_of(const std::vector<const void*>& ptrs) const {
        for(size_t i = 0; i < ptrs.size(); ++i)
            if(is(ptrs[i])) return true;
        return false;
    }
 
    template <typename T>
    bool member_of(const T& ref) const {
        const void* addr_begin = reinterpret_cast<const void*>(&ref);
        const void* addr_end = reinterpret_cast<const void*>(reinterpret_cast<size_t>(addr_begin) + sizeof(T));
        return ptr >= addr_begin && ptr < addr_end;
    }
};
 
}
}