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  1. #include <iostream>
  2. #include <cassert>
  3.  
  4. #include <utility> //For std::forward.
  5.  
  6. namespace Memory
  7. {
  8.     template<typename Type, typename ...Args>
  9.     Type *Allocate(Args&& ...args)
  10.     {
  11.         //Allocate memory using 'malloc'.
  12.         Type *ptr = static_cast<Type*>(malloc(sizeof(Type)));
  13.         assert(ptr && "We're probably out of memory.");
  14.  
  15.         //Manually call constructor, forwarding the arguments to the constructor.
  16.         new (ptr) Type(std::forward<Args>(args)...);
  17.  
  18.         //Return the pointer.
  19.         return ptr;
  20.     }
  21.  
  22.     template<typename Type>
  23.     void Deallocate(Type* &ptr) //Reference to a pointer. Huh, never had to use that before.
  24.     {
  25.         //Comment this assert out if you like the ability to pass null to 'delete'.
  26.         assert(ptr && "Trying to allocate an already NULL pointer.");
  27.  
  28.         //Call the destructor manually.
  29.         ptr->~Type();
  30.  
  31.         //Deallocate the memory.
  32.         free(ptr);
  33.  
  34.         //Nullify the pointer (we got a reference to a pointer, so this is nulling the pointer that was passed into the function).
  35.         //Comment this line out if you want to do the nulling yourself.
  36.         ptr = nullptr;
  37.     }
  38.  
  39. } //End of namespace.
  40.  
  41. class MyClass
  42. {
  43.     public:	
  44. 	MyClass(const std::string &str, int value)
  45. 	{
  46. 		std::cout << "MyClass(" << str << "," << value << ")" << std::endl;
  47. 	}
  48.  
  49. 	~MyClass()
  50. 	{
  51. 		std::cout << "~MyClass()" << std::endl;
  52. 	}
  53. };
  54.  
  55. int main()
  56. {
  57. 	std::cout << "---------- Start ----------" << std::endl;
  58.  
  59. 	MyClass *myClass = Memory::Allocate<MyClass>("Hello", 357);
  60.  
  61. 	std::cout << "Pointer address: " << myClass << std::endl;
  62. 	std::cout << "...program does stuff..." << std::endl;
  63.  
  64. 	Memory::Deallocate(myClass);
  65.  
  66. 	std::cout << "---------- End ----------" << std::endl;
  67. 	std::cout << "Pointer address: " << myClass << std::endl;
  68.  
  69. 	return 0;
  70. }
Success #stdin #stdout 0s 16064KB
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stdin
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Standard input is empty
stdout
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---------- Start ----------
MyClass(Hello,357)
Pointer address: 0x2b2a9bbf2c30
...program does stuff...
~MyClass()
---------- End ----------
Pointer address: 0
https://ideone.com/MhD0Or
language:
C++14 (gcc 8.3)
created:
6 years ago
visibility:
public

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