boost是否具有用于数组向量的智能指针？

Question

This is to hold a data like

double **a;
a = new (double*)[100];
for (int i=0; i<100; ++i) {
   a[i] = new double[99];
}

The ptr_vector can include a vector of pointers. But it does not seem supporting customized deleter to free an array.

One solution is that I can create a new class that manages 99 doubles, and use ptr_vector to hold 100 of the classes?

Answer 1

The best approach is to use the Standard Library . std::vector saves you from having to worry about memory management and having to set the vector's size.

std::vector<std::vector<double>> a;

You can also use std::unique_ptr , but it is more bothersome to allocate dynamic memory. However, since it is a std::unique_ptr is a smart pointer when the object destructs/runs out of scope, memory is automatically deallocated.

std::unique_ptr<std::unique_ptr<double>[]> a(new std::unique_ptr<double>[100]);
  for (i=0; i <100; i++)
      a[i] = std::unique_ptr<int[]>(new int[99]);

The above works, but it defeats the intent of std::unique_ptr which is to save you from using pointers and automatically allocating and deallocating memory.