gcc/testsuite/gdc.test/fail_compilation/test19661.d

/*
EXTRA_FILES: imports/imp19661.d
TEST_OUTPUT:
---
fail_compilation/test19661.d(11): Error: variables cannot be initialized with an expression of type `void`. Use `void` initialization instead.
---
*/

module ice19661;

immutable bool testModule = testFunctionMembers!();

void testFunctionMembers()() {
    import imports.imp19661 : isFunction;
    foreach(member; __traits(allMembers, ice19661)) {
        bool b = isFunction!(__traits(getMember, ice19661, member));
    }
}