In C++11 it is legal to write, for instance:
int b = (some_function_returning_void(), 1020);
And you'll get back 1020. But it won't let you write:
int b = (static_assert(2 > 1, "all is lost"), 304);
The documentation explains the legal spots where static_assert (a keyword, apparently) can occur:
A static assert declaration may appear at block scope (as a block declaration) and inside a class body (as a member declaration)
Just for the heck of it I tried a couple things until this worked:
int b = ({static_assert(2 > 1, "all is lost"); 304;});
But with -Wpedantic I get "warning: ISO C++ forbids braced-groups within expressions". Interestingly, these are called "statement expressions" and used in the Linux kernel.
But let's imagine I want to stay -Wpedantic. Are there any clean workarounds?
As @dyp mentioned in the comments, you can abuse the comma operator and a lambda-expression :
([]{static_assert(true,"");}, 42)