Emilio Cobos Álvarez
b2e224354b
Using operator= is not quite sound in presence of destructors and operator overloading. It's perfectly fine to assume that the left-hand-side of an operator= expression is valid memory, however we're using uninitialized memory here, that may not be the case. Use placement new to properly construct tagged unions. I don't need this with any urgency, but it's the right thing to do in presence of complex types, and the current code seems a bomb waiting to explode :)
38 lines
620 B
C++
38 lines
620 B
C++
#define MUST_USE_FUNC __attribute__((warn_unused_result))
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#define MUST_USE_STRUCT __attribute__((warn_unused))
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#define MUST_USE_ENUM /* nothing */
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#include <cstdarg>
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#include <cstdint>
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#include <cstdlib>
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#include <new>
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template<typename T>
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struct MUST_USE_STRUCT MaybeOwnedPtr {
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enum class MUST_USE_ENUM Tag : uint8_t {
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Owned,
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None,
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};
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struct Owned_Body {
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T *_0;
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};
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Tag tag;
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union {
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Owned_Body owned;
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};
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};
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template<typename T>
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struct MUST_USE_STRUCT OwnedPtr {
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T *ptr;
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};
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extern "C" {
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MUST_USE_FUNC MaybeOwnedPtr<int32_t> maybe_consume(OwnedPtr<int32_t> input);
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} // extern "C"
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