是否可以使用std :: fill与2d C风格的数组？ [英] Is it possible to use std::fill with a 2d C-style array?

问题描述

假设我有： unsigned char my2darray [A] [B];

使用 std :: fill 将2d数组的所有值设置为非0值？

可以使用向量，但这是性能关键代码，我不能承受动态分配。

目前在代码中使用的是 memset（my2darray，0x12，sizeof（my2darray））; / code>但是我想用 std :: fill 替换所有 memset

解决方案

是的，因为2d数组仍然是被分配为连续内存块的一系列元素。

  std :: fill（
& my2darray [0] [0]，
& my2darray [0] [0] + sizeof（my2darray）/ sizeof（my2darray [0] [0]），
 none_zero_value）; 
  

Suppose that I have: unsigned char my2darray[A][B];

Is it possible to use std::fill to set all values of the 2d array to a non-0 value?

I know a vector can be used but this is performance critical code and I can't afford dynamic allocations. Unfortunately, no C++11 is allowed.

Currently used in the code is memset(my2darray, 0x12, sizeof(my2darray)); but I want to replace all memset with std::fill if possible, as the type of the array could become a class in future.

Answers which work for any type, not just chars, appreciated.

解决方案

Yes, because a 2d array is still a sequence of elements that are allocated as a contiguous block of memory.

    std::fill (
      &my2darray[0][0],
      &my2darray[0][0] + sizeof(my2darray) / sizeof(my2darray[0][0]),
      none_zero_value);

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