ToString

UTH::ToString

UTH::ToString is the method used by macros to output a param as a string.
UTH provides a default implementation that tries to call the method ToString from an element if there is one (pseudo code):

template <typename T>
std::string UTH::ToString(const T& _elem)
{
    if <has_member_ToString>
        return _elem.ToString();
    else
        return "";
}

Thus, if the method ToString is already defined within the class, it will be automatically called:

class MyClass
{
    int value;
    std::string ToString() const { return std::to_string(value); }
};

If such a method is not provided, no output string will be output during testing (which makes test debugging harder).

Template Specialization

If the class element doesn't implement such a method and you wish to not implement it inside your class, you just need to implement a template specialization of UTH::ToString above the tests:

// Vec2.hpp
struct Vec2
{
    float x = 0.0f;
    float y = 0.0f;

    static bool Equals(const Vec2& _v1, const Vec2& _v2)
    {
        return _v1.x == _v2.x && _v1.y == _v2.y;
    }
};


// main.cpp
#include "Vec2.hpp"

// Template specialization
template <>
std::string UTH::ToString(const Vec2& _elem)
{
    return "X: " + std::to_string(_elem.x) + "\tY: " + std::to_string(_elem.y);
}

int main()
{
    SA_UTH_INIT();

    Vec2 v1{ 1.0f, 2.0f };
    Vec2 v2{ 3.0f, 5.0f };

    SA_UTH_SF(Vec2::Equals, v1, v2);

    SA_UTH_EXIT()
}

Output in default verbosity:

[SA-UTH] Failure: Vec2::Equals(v1, v2) -- l<line>
v1
X: 1.000000    Y: 2.000000
v2
X: 3.000000    Y: 5.000000

Template Partial Specialization

For advanced ToString implementation, partial template specialization is easily possible.

// Vec2.hpp
template <typename T>
struct Vec2
{
    T x = 0.0f;
    T y = 0.0f;

    static bool Equals(const Vec2<T>& _v1, const Vec2<T>& _v2)
    {
        return _v1.x == _v2.x && _v1.y == _v2.y;
    }
};


// main.cpp
#include "Vec2.hpp"

// Template partial specialization
template <typename T>
std::string UTH::ToString(const Vec2<T>& _elem)
{
    return "X: " + std::to_string(_elem.x) + "\tY: " + std::to_string(_elem.y);
}

int main()
{
    SA_UTH_INIT();

    Vec2 v1{ 1.0f, 2.0f };
    Vec2 v2{ 3.0f, 5.0f };

    SA_UTH_SF(Vec2::Equals, v1, v2);

    SA_UTH_EXIT()
}

Output in default verbosity:

[SA-UTH] Failure: Vec2::Equals(v1, v2) -- l<line>
v1
X: 1.000000    Y: 2.000000
v2
X: 3.000000    Y: 5.000000

More Examples

• main_success.cpp for ToString example.
• main_failure.cpp for Stringizer implementation (not requiered) example.
• See SA-Maths for Stringizer (required) implementation:
  • Vector3 declaration
  • Vector3 definition