src/dawn/common/PlacementAllocated.h

// Copyright 2020 The Dawn & Tint Authors
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#ifndef SRC_DAWN_COMMON_PLACEMENTALLOCATED_H_
#define SRC_DAWN_COMMON_PLACEMENTALLOCATED_H_

#include <cstddef>

namespace dawn {

class PlacementAllocated {
  public:
    // Delete the default new operator so this can only be created with placement new.
    void* operator new(size_t) = delete;

    void* operator new(size_t size, void* ptr) {
        // Pass through the pointer of the allocation. This is essentially the default
        // placement-new implementation, but we must define it if we delete the default
        // new operator.
        return ptr;
    }

    void operator delete(void* ptr) {
        // Object is placement-allocated. Don't free the memory.
    }

    void operator delete(void*, void*) {
        // This is added to match new(size_t size, void* ptr)
        // Otherwise it triggers C4291 warning in MSVC
    }
};

}  // namespace dawn

#endif  // SRC_DAWN_COMMON_PLACEMENTALLOCATED_H_