如何在c ++中将void *转换为float（*）[3]？

Question

This is the code snippet.

typedef struct Lib3dsMesh {
 //..
 float (*vertices)[3]; 
 //..
}


void* lib3ds_util_realloc_array(void *ptr, int old_size, int new_size, int  element_size) {
    // Do something here.
    return ptr;
}


mesh->vertices = lib3ds_util_realloc_array(mesh->vertices, mesh->nvertices, nvertices, 3 * sizeof(float));

When I compile this code in visual c++ it returns error "Cannot convert from void* to float(*)[3]".

I would like to know how to cast void * to float (*vertices)[3];

Answer 1

vertices is a pointer to a 3-element array of float . To do a cast from one pointer type to another, you generally use static_cast :

void* result = lib3ds_util_realloc_array(
    mesh->vertices, mesh->nvertices, nvertices, 3 * sizeof(float));
mesh-vertices = static_cast<float (*)[3]>(result);