Comparisons.h

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/*
 * This file is a part of the Biology project by eons LLC.
 * Biology (aka Develop Biology) is a framework for approaching software
 * development from a natural sciences perspective.
 *
 * Copyright (C) 2024 Séon O'Shannon & eons LLC
 *
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU Affero General Public License as
 * published by the Free Software Foundation, either version 3 of the
 * License, or (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU Affero General Public License for more details.
 *
 * You should have received a copy of the GNU Affero General Public License
 * along with this program.  If not, see <https://www.gnu.org/licenses/>.
 */
 
#pragma once
 
#include "bio/common/ByteStream.h"
#include "bio/common/Cast.h"
#include "bio/common/type/EnableIf.h"
#include "bio/common/type/IsPointer.h"
#include "bio/common/type/IsPrimitive.h"
#include "bio/common/type/NormalizeTypeName.h"
#include "bio/common/type/RemovePointer.h"
#include "bio/common/type/TypeName.h"
#include "bio/common/macro/Macros.h"
#include <cstring>
 
namespace bio {
namespace arrangement_detail {
 
inline bool IsTypeNameEquivalent(
    const String& externalName,
    const ImmutableString& internalName
)
{
    if (externalName == internalName)
    {
        return true;
    }
    // Allow for compiler formatting differences like "class/struct/const" qualifiers.
    String normalizedExternal = type::NormalizeTypeName(externalName);
    String normalizedInternal = type::NormalizeTypeName(String(internalName));
    return normalizedExternal == normalizedInternal;
}
 
template < typename T >
inline typename type::EnableIf<
    type::IsPrimitiveImplementation< T >::sValue,
    bool
>::Type CompareExternalPrimitive(
    const ByteStream& external,
    const T& internalValue
)
{
    if (external.GetSize() != sizeof(T))
    {
        return false;
    }
    const void* raw = external.DirectAccess();
    BIO_SANITIZE(raw, , return false)
    T externalValue = internalValue;
    ::std::memcpy(&externalValue, raw, sizeof(T));
    if (IsTypeNameEquivalent(external.GetTypeName(), type::TypeName< T >()))
    {
        return internalValue == externalValue;
    }
    // Allow wrapped primitives to compare by value even if type names differ.
    return internalValue == externalValue;
}
 
template < typename T >
inline typename type::EnableIf<
    !type::IsPrimitiveImplementation< T >::sValue,
    bool
>::Type CompareExternalPrimitive(
    const ByteStream&,
    const T&
)
{
    return false;
}
 
template < typename T >
inline typename type::EnableIf<
    type::IsPointerImplementation< T >::sValue,
    bool
>::Type CompareExternalPointer(
    const ByteStream& external,
    const T& internalValue
)
{
    if (!external.IsPointerLike())
    {
        return false;
    }
    const void* raw = external.DirectAccess();
    BIO_SANITIZE(raw, , return false)
    if (external.GetSize() == sizeof(T))
    {
        const T* externalPtr = ForceCast< const T* >(raw);
        BIO_SANITIZE(externalPtr, , return false)
        return internalValue == *externalPtr;
    }
    if (type::IsPointerWrapper< T >::sValue && external.GetSize() == sizeof(typename type::RemovePointer< T >::Type*))
    {
        typedef typename type::RemovePointer< T >::Type Pointee;
        Pointee* const* externalPtr = ForceCast< Pointee* const* >(raw);
        BIO_SANITIZE(externalPtr, , return false)
        return internalValue == *externalPtr;
    }
    return false;
}
 
template < typename T >
inline typename type::EnableIf<
    !type::IsPointerImplementation< T >::sValue,
    bool
>::Type CompareExternalPointer(
    const ByteStream&,
    const T&
)
{
    return false;
}
 
} //arrangement_detail namespace
} //bio namespace