74 lines
1.8 KiB
C
74 lines
1.8 KiB
C
|
#pragma once
|
||
|
|
||
|
#include "CoreTypes.h"
|
||
|
#include "Templates/Utility.h"
|
||
|
#include "TypeTraits/TypeTraits.h"
|
||
|
|
||
|
NAMESPACE_REDCRAFT_BEGIN
|
||
|
NAMESPACE_MODULE_BEGIN(Redcraft)
|
||
|
NAMESPACE_MODULE_BEGIN(Utility)
|
||
|
|
||
|
/**
|
||
|
* A helper class which replaces T& as a function parameter when the reference is
|
||
|
* intended to be retained by the function (e.g. as a class member). The benefit
|
||
|
* of this class is that it is a compile error to pass an rvalue which might otherwise
|
||
|
* bind to a const reference, which is dangerous when the reference is retained.
|
||
|
*
|
||
|
* struct FRAIIType
|
||
|
* {
|
||
|
* explicit FRAIIType(TRetainedRef<const FThing> InThing) : Ref(InThing) { }
|
||
|
*
|
||
|
* void DoSomething() { Ref.Something(); }
|
||
|
*
|
||
|
* FThing& Ref;
|
||
|
* };
|
||
|
*
|
||
|
*/
|
||
|
template <typename T>
|
||
|
struct TRetainedRef
|
||
|
{
|
||
|
/** Retain a non-const lvalue reference. */
|
||
|
FORCEINLINE constexpr TRetainedRef(T& InRef) : Ref(InRef) { }
|
||
|
|
||
|
/** Can't retain a rvalue reference. */
|
||
|
TRetainedRef(const T& ) = delete;
|
||
|
TRetainedRef( T&&) = delete;
|
||
|
TRetainedRef(const T&&) = delete;
|
||
|
|
||
|
/** @return The managed reference. */
|
||
|
FORCEINLINE constexpr operator T&() const { return Ref; }
|
||
|
FORCEINLINE constexpr T& Get() const { return Ref; }
|
||
|
|
||
|
private:
|
||
|
|
||
|
T& Ref;
|
||
|
|
||
|
};
|
||
|
|
||
|
template <typename T>
|
||
|
struct TRetainedRef<const T>
|
||
|
{
|
||
|
/** Retain a non-const lvalue reference. */
|
||
|
FORCEINLINE constexpr TRetainedRef(T& InRef) : Ref(InRef) { }
|
||
|
|
||
|
/** Retain a const lvalue reference. */
|
||
|
FORCEINLINE constexpr TRetainedRef(const T& InRef) : Ref(InRef) { }
|
||
|
|
||
|
/** Can't retain a rvalue reference. */
|
||
|
TRetainedRef( T&&) = delete;
|
||
|
TRetainedRef(const T&&) = delete;
|
||
|
|
||
|
/** @return The managed reference. */
|
||
|
FORCEINLINE constexpr operator const T&() const { return Ref; }
|
||
|
FORCEINLINE constexpr const T& Get() const { return Ref; }
|
||
|
|
||
|
private:
|
||
|
|
||
|
const T& Ref;
|
||
|
|
||
|
};
|
||
|
|
||
|
NAMESPACE_MODULE_END(Utility)
|
||
|
NAMESPACE_MODULE_END(Redcraft)
|
||
|
NAMESPACE_REDCRAFT_END
|