Compile error with BOOST_REQUIRE_THROW

[martin.desharnais@…]

I recently post this email on the boost-users mailing list:

Hi, I've just found that we have a compiler error when using the BOOST_REQUIRE_THROW macro in a if/else statement with implicit block. Let's have an example:

BOOST_AUTO_TEST_CASE(foo) {

if(true)

BOOST_REQUIRE_THROW(throw std::exception(), std::exception);

else

BOOST_REQUIRE_THROW(throw std::exception(), std::exception);

}

Will fail with:

file.cpp: In member function ‘void foo::test_method()’: file.cpp:184:2: error: ‘else’ without a previous ‘if’

To make it work, we need to put explicit block:

BOOST_AUTO_TEST_CASE(foo) {

if(true) {

BOOST_REQUIRE_THROW(throw std::exception(), std::exception);

} else {

BOOST_REQUIRE_THROW(throw std::exception(), std::exception);

}

}

Wouldn't it be possible to add this block in the macro so library users don't have to care about?

And got this answer:

BOOST_REQUIRE_THROW expands into a try { ... } catch { ... } block. Such a block is a valid single statement, but if you put a ; at the end of the catch block, that semicolon terminates the if statement. [...] The macro could be enclosed in a do { .... } while (0) construct in order to make it syntactically appear more like a single statement that is terminated with a semicolon.

[Gennadiy Rozental]

Fixed in trunk