Use of std::deque and clang compiler

Question

It seems that std::deque does not allow to use it in a recursive way with clang on osx when not using libstdc++ (10.9+ target)

#include <deque>

struct node { std::deque<node> childs; };

int main() {
    node n;
}

This simple code compile with clang only if I set MACOS_DEPLOYMENT_TARGET=10.8 (because the clang compiler links with libstdc++) but it gives a lot of errors if I try to compile with libc++ (default c++ target on 10.9+), while with gcc 4/5 it works without problems...

It's a compiler bug or the standard does not allow this? It's seems a quite obvious use of a container...

Note that there are containers in `boost.container` library that allow this. — juanchopanza, Nov 18 '16 at 09:04

score 1 · Accepted Answer · answered Nov 18 '16 at 08:48

In general, you should not expect this code to compile. To be sure that it compiles with any standard-compliant compiler you must use an extra level of indirection in one of the following or similar ways:

struct node { std::deque<node> *children; };
struct node { std::unique_ptr<std::deque<node>> children; };
struct node { std::deque<node*> children; };

Use of std::deque and clang compiler

1 Answers1