catch2/include/internal/catch_evaluate.hpp

/*
 *  Created by Phil on 04/03/2011.
 *  Copyright 2011 Two Blue Cubes Ltd. All rights reserved.
 *
 *  Distributed under the Boost Software License, Version 1.0. (See accompanying
 *  file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
 */
#ifndef TWOBLUECUBES_CATCH_EVALUATE_HPP_INCLUDED
#define TWOBLUECUBES_CATCH_EVALUATE_HPP_INCLUDED

#ifdef _MSC_VER
#pragma warning(push)
#pragma warning(disable:4389) // '==' : signed/unsigned mismatch
#pragma warning(disable:4312) // Converting int to T* using reinterpret_cast (issue on x64 platform)
#endif

#include <cstddef>

namespace Catch {
namespace Internal {

    enum Operator {
        IsEqualTo,
        IsNotEqualTo,
        IsLessThan,
        IsGreaterThan,
        IsLessThanOrEqualTo,
        IsGreaterThanOrEqualTo
    };

    const char* operatorName(Operator op);

    template<typename T>
    T& opCast(T const& t) { return const_cast<T&>(t); }
    std::nullptr_t opCast(std::nullptr_t);


    // So the compare overloads can be operator agnostic we convey the operator as a template
    // enum, which is used to specialise an Evaluator for doing the comparison.
    template<typename T1, typename T2, Operator Op>
    struct Evaluator{};

    template<typename T1, typename T2>
    struct Evaluator<T1, T2, IsEqualTo> {
        static bool evaluate( T1 const& lhs, T2 const& rhs) {
            return bool( opCast( lhs ) ==  opCast( rhs ) );
        }
    };
    template<typename T1, typename T2>
    struct Evaluator<T1, T2, IsNotEqualTo> {
        static bool evaluate( T1 const& lhs, T2 const& rhs ) {
            return bool( opCast( lhs ) != opCast( rhs ) );
        }
    };
    template<typename T1, typename T2>
    struct Evaluator<T1, T2, IsLessThan> {
        static bool evaluate( T1 const& lhs, T2 const& rhs ) {
            return bool( opCast( lhs ) < opCast( rhs ) );
        }
    };
    template<typename T1, typename T2>
    struct Evaluator<T1, T2, IsGreaterThan> {
        static bool evaluate( T1 const& lhs, T2 const& rhs ) {
            return bool( opCast( lhs ) > opCast( rhs ) );
        }
    };
    template<typename T1, typename T2>
    struct Evaluator<T1, T2, IsGreaterThanOrEqualTo> {
        static bool evaluate( T1 const& lhs, T2 const& rhs ) {
            return bool( opCast( lhs ) >= opCast( rhs ) );
        }
    };
    template<typename T1, typename T2>
    struct Evaluator<T1, T2, IsLessThanOrEqualTo> {
        static bool evaluate( T1 const& lhs, T2 const& rhs ) {
            return bool( opCast( lhs ) <= opCast( rhs ) );
        }
    };

    template<Operator Op, typename T1, typename T2>
    bool applyEvaluator( T1 const& lhs, T2 const& rhs ) {
        return Evaluator<T1, T2, Op>::evaluate( lhs, rhs );
    }

    // This level of indirection allows us to specialise for integer types
    // to avoid signed/ unsigned warnings

    // "base" overload
    template<Operator Op, typename T1, typename T2>
    bool compare( T1 const& lhs, T2 const& rhs ) {
        return Evaluator<T1, T2, Op>::evaluate( lhs, rhs );
    }

    // unsigned X to int
    template<Operator Op> bool compare( unsigned int lhs, int rhs ) {
        return applyEvaluator<Op>( lhs, static_cast<unsigned int>( rhs ) );
    }
    template<Operator Op> bool compare( unsigned long lhs, int rhs ) {
        return applyEvaluator<Op>( lhs, static_cast<unsigned int>( rhs ) );
    }
    template<Operator Op> bool compare( unsigned char lhs, int rhs ) {
        return applyEvaluator<Op>( lhs, static_cast<unsigned int>( rhs ) );
    }

    // unsigned X to long
    template<Operator Op> bool compare( unsigned int lhs, long rhs ) {
        return applyEvaluator<Op>( lhs, static_cast<unsigned long>( rhs ) );
    }
    template<Operator Op> bool compare( unsigned long lhs, long rhs ) {
        return applyEvaluator<Op>( lhs, static_cast<unsigned long>( rhs ) );
    }
    template<Operator Op> bool compare( unsigned char lhs, long rhs ) {
        return applyEvaluator<Op>( lhs, static_cast<unsigned long>( rhs ) );
    }

    // int to unsigned X
    template<Operator Op> bool compare( int lhs, unsigned int rhs ) {
        return applyEvaluator<Op>( static_cast<unsigned int>( lhs ), rhs );
    }
    template<Operator Op> bool compare( int lhs, unsigned long rhs ) {
        return applyEvaluator<Op>( static_cast<unsigned int>( lhs ), rhs );
    }
    template<Operator Op> bool compare( int lhs, unsigned char rhs ) {
        return applyEvaluator<Op>( static_cast<unsigned int>( lhs ), rhs );
    }

    // long to unsigned X
    template<Operator Op> bool compare( long lhs, unsigned int rhs ) {
        return applyEvaluator<Op>( static_cast<unsigned long>( lhs ), rhs );
    }
    template<Operator Op> bool compare( long lhs, unsigned long rhs ) {
        return applyEvaluator<Op>( static_cast<unsigned long>( lhs ), rhs );
    }
    template<Operator Op> bool compare( long lhs, unsigned char rhs ) {
        return applyEvaluator<Op>( static_cast<unsigned long>( lhs ), rhs );
    }

    // pointer to long (when comparing against NULL)
    template<Operator Op, typename T> bool compare( long lhs, T* rhs ) {
        return Evaluator<T*, T*, Op>::evaluate( reinterpret_cast<T*>( lhs ), rhs );
    }
    template<Operator Op, typename T> bool compare( T* lhs, long rhs ) {
        return Evaluator<T*, T*, Op>::evaluate( lhs, reinterpret_cast<T*>( rhs ) );
    }

    // pointer to int (when comparing against NULL)
    template<Operator Op, typename T> bool compare( int lhs, T* rhs ) {
        return Evaluator<T*, T*, Op>::evaluate( reinterpret_cast<T*>( lhs ), rhs );
    }
    template<Operator Op, typename T> bool compare( T* lhs, int rhs ) {
        return Evaluator<T*, T*, Op>::evaluate( lhs, reinterpret_cast<T*>( rhs ) );
    }

    // long long to unsigned X
    template<Operator Op> bool compare( long long lhs, unsigned int rhs ) {
        return applyEvaluator<Op>( static_cast<unsigned long>( lhs ), rhs );
    }
    template<Operator Op> bool compare( long long lhs, unsigned long rhs ) {
        return applyEvaluator<Op>( static_cast<unsigned long>( lhs ), rhs );
    }
    template<Operator Op> bool compare( long long lhs, unsigned long long rhs ) {
        return applyEvaluator<Op>( static_cast<unsigned long>( lhs ), rhs );
    }
    template<Operator Op> bool compare( long long lhs, unsigned char rhs ) {
        return applyEvaluator<Op>( static_cast<unsigned long>( lhs ), rhs );
    }

    // unsigned long long to X
    template<Operator Op> bool compare( unsigned long long lhs, int rhs ) {
        return applyEvaluator<Op>( static_cast<long>( lhs ), rhs );
    }
    template<Operator Op> bool compare( unsigned long long lhs, long rhs ) {
        return applyEvaluator<Op>( static_cast<long>( lhs ), rhs );
    }
    template<Operator Op> bool compare( unsigned long long lhs, long long rhs ) {
        return applyEvaluator<Op>( static_cast<long>( lhs ), rhs );
    }
    template<Operator Op> bool compare( unsigned long long lhs, char rhs ) {
        return applyEvaluator<Op>( static_cast<long>( lhs ), rhs );
    }

    // pointer to long long (when comparing against NULL)
    template<Operator Op, typename T> bool compare( long long lhs, T* rhs ) {
        return Evaluator<T*, T*, Op>::evaluate( reinterpret_cast<T*>( lhs ), rhs );
    }
    template<Operator Op, typename T> bool compare( T* lhs, long long rhs ) {
        return Evaluator<T*, T*, Op>::evaluate( lhs, reinterpret_cast<T*>( rhs ) );
    }

    // pointer to nullptr_t (when comparing against nullptr)
    template<Operator Op, typename T> bool compare( std::nullptr_t, T* rhs ) {
        return Evaluator<T*, T*, Op>::evaluate( nullptr, rhs );
    }
    template<Operator Op, typename T> bool compare( T* lhs, std::nullptr_t ) {
        return Evaluator<T*, T*, Op>::evaluate( lhs, nullptr );
    }

} // end of namespace Internal
} // end of namespace Catch

#ifdef _MSC_VER
#pragma warning(pop)
#endif

#endif // TWOBLUECUBES_CATCH_EVALUATE_HPP_INCLUDED