How to properly replace global new & delete operators

by

That’s not how this works. You replace the two operators, and this is done at link time. All you need to do is write a single TU that defines these operators and link it into the mix. Nobody else ever needs to know about this:

// optional_ops.cpp

void * operator new(std::size_t n) throw(std::bad_alloc)
{
  //...
}
void operator delete(void * p) throw()
{
  //...
}

In principle, there’s no need for any header files to declare these functions (operator new, operator delete), since the declarations of those two functions are already hardcoded into the language, if you will. However, the names std, std::bad_alloc and std::size_t are not predeclared, so you will probably want to include <new> or some other header to provide those names.

In C++11 and beyond, you can alternatively use decltype(sizeof(0)) to get the size of the first parameter in a way that doesn’t require any kind of library. C++11 also has a simpler exception model without dynamic exception specifications (which were finally removed from the language entirely in C++17).

void * operator new(decltype(sizeof(0)) n) noexcept(false)
{
  //...
}

More Related Contents:

  1. How to get memory usage under Windows in C++
  2. track C++ memory allocations
  3. delete vs delete[] operators in C++
  4. Is it safe to delete a NULL pointer?
  5. Operator new initializes memory to zero
  6. How to debug heap corruption errors?
  7. Qt5 Static Build yields Failed to load platform plugin “windows”
  8. MSVCP140.dll missing
  9. Exporting a C++ class from a DLL
  10. What is the proper OpenGL initialisation on Intel HD 3000?
  11. Multithreaded Rendering on OpenGL
  12. How to deploy a Qt application on Windows?
  13. std::vector and contiguous memory of multidimensional arrays
  14. What is the difference between WM_QUIT, WM_CLOSE, and WM_DESTROY in a windows program?
  15. Pointer-to-pointer dynamic two-dimensional array
  16. Can I pass std::string to a DLL?
  17. Using CreateWindowEx to Make a Message-Only Window
  18. Windows Unicode C++ Stream Output Failure
  19. Best method for storing this pointer for use in WndProc
  20. Is there a way to get the string representation of HRESULT value using win API?
  21. How do I use the MinGW gdb debugger to debug a C++ program in Windows?
  22. How does delete work? [duplicate]
  23. Fatal error: “No Target Architecture” in Visual Studio
  24. If a 32-bit integer overflows, can we use a 40-bit structure instead of a 64-bit long one?
  25. Passing reference to STL vector over dll boundary
  26. Memory limitations in a 64-bit .Net application?
  27. Visual Studio 2013: CL.exe exited with code -1073741515
  28. What happen to pointers when vectors need more memory and realocate memory?
  29. C++ delete does not free all memory (Windows)
  30. How can I cin and cout some unicode text?

Leave a Comment