What is the use of ** in C++?

Question

Segment computeSegment(Triangle& t, float z)
{
    Vertex** vs = t.vertices;
    // ...
}

Here, Vertex is the name of a structure. Can you tell me what is the meaning of ** in Vertex** vs = t.vertices;?

Given the names of the variables, I assume that a `Triangle` has a member `vertices` that is a pointer to an array of pointers to `Vertex`es so `vs[0]` would give you a *pointer* to the first vertex. — 5gon12eder, Jan 28 '15 at 20:22
Without `**` we could not have `***`, and then we could not have a [three star programmer](http://c2.com/cgi/wiki?ThreeStarProgrammer) — Yakk - Adam Nevraumont, Jan 28 '15 at 20:29

score 2 · Answer 1 · answered Jan 28 '15 at 20:14

2

Vertex* is pointer-to-Vertex, so Vertex** is pointer-to-pointer-to-Vertex -- one more level of indirection.

For example:

int i = 0;
int * iPtr = &i;        // iPtr -> i
int ** iPtrPtr = &iPtr; // iPtrPtr -> iPtr -> i

answered Jan 28 '15 at 20:14

cdhowie

1 Answers1