jiuyiUniapp/service/node_modules/react-native/Libraries/Required/RCTRequired.h

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2025-02-13 09:59:20 +08:00
/*
* Copyright (c) Meta Platforms, Inc. and affiliates.
*
* This source code is licensed under the MIT license found in the
* LICENSE file in the root directory of this source tree.
*/
#include <utility>
// The inliner doesn't take into account ARC optimizations that may occur after
// inlining when computing the inline cost of an ObjC++ function. Here we make
// the inlining decisions to avoid unnecessary code bloat. In effect RCTRequired
// is a cost-free abstraction in non-DEBUG mode. In DEBUG mode we don't force
// inlining for ease of debugging.
#if DEBUG
#define RCTREQUIRED_INLINE inline
#else
#define RCTREQUIRED_INLINE __attribute__((always_inline)) inline
#endif
/**
RCTRequired<T> uses the compiler to enforce definition of a struct member
(primitives, pointers, or objects).
Internally, we use an implicit constructor without a default, so there has to
be an initial value.
Usage:
@code
struct S {
RCTRequired<int> i;
RCTRequired<NSString *> str;
NSString *optionalStr;
};
S options = {
.i = 0, // warning if omitted
.str = @"Hello World", // warning if omitted
};
@endcode
*/
template <typename T>
struct RCTRequired {
/// Pass-through constructor (allows for implicit conversion) for wrapped type
/// T
template <typename... Args>
RCTREQUIRED_INLINE RCTRequired(Args&&... args)
: _t(std::forward<Args>(args)...) {
static_assert(
sizeof...(Args) > 0,
"Required struct member not initialized. Expand assert trace to see where this was triggered.");
}
RCTREQUIRED_INLINE
RCTRequired(const RCTRequired&) = default;
RCTREQUIRED_INLINE
RCTRequired(RCTRequired&&) = default;
RCTREQUIRED_INLINE
RCTRequired& operator=(const RCTRequired&) = default;
RCTREQUIRED_INLINE
RCTRequired& operator=(RCTRequired&&) = default;
RCTREQUIRED_INLINE
~RCTRequired() = default;
/// Public accessor for private storage (Use when implicit conversion is
/// impracticable)
RCTREQUIRED_INLINE
const T& get() const {
return _t;
}
RCTREQUIRED_INLINE
T& get() {
return _t;
}
// Implicit conversion
RCTREQUIRED_INLINE
operator T() const {
return _t;
}
RCTREQUIRED_INLINE
operator T&() {
return _t;
}
private:
T _t;
};