Passing " &> " shell-command string to shell

Consider the following function,

function! Compile()
:cmd_string = "g++ -std=c++11 " . expand("%") . " &> " . expand("%:r") . ".log"
:execute "silent !" . cmd_string
endfunction

The simple goal is to compile with g++, writing any compiler output to a log file.
I'm having trouble passing the " &> " term to the shell.
Suppose % expands to file.cpp, then adding the line,

:execute "!echo " . cmd_string

Produces:

g++ -std=c++11 file.cpp

So the " &> " doesn't even make it to the shell. Any help is much appreciated.

--
--
You received this message from the "vim_use" maillist.
Do not top-post! Type your reply below the text you are replying to.
For more information, visit http://www.vim.org/maillist.php

---
You received this message because you are subscribed to the Google Groups "vim_use" group.
To unsubscribe from this group and stop receiving emails from it, send an email to vim_use+unsubscribe@googlegroups.com.
For more options, visit https://groups.google.com/groups/opt_out.