DOCTEST_CHECK_THROWS_WITH_AS fails to work with dependant exception type

[YarikTH]

Description

I tried to write a templated test case. In this test case, I need to check the thrown exception. But compilation failed because my exception type depends on the tested type. Unfortunately deep inside doctest's macroses (namely in DOCTEST_ASSERT_THROWS_AS) code is not ready to dependant exception types.

Steps to reproduce

https://godbolt.org/z/f5M4on

#define DOCTEST_CONFIG_IMPLEMENT_WITH_MAIN
#include <https://raw.githubusercontent.com/onqtam/doctest/2.4.1/doctest/doctest.h>
#include <exception>

template<class T>
struct Json
{
    using out_of_range = std::out_of_range;

    T get()
    {
        throw out_of_range( "Out of range" );
        return T();
    }
};

TEST_CASE_TEMPLATE("My testcase", T,
                   Json<int>)
{
    T json;
    DOCTEST_CHECK_THROWS_WITH_AS(json.get(), "Out of range", typename T::out_of_range);
}

Example output

x86-64 gcc 7.3 (Editor #1, Compiler #1) C++
x86-64 gcc 7.3
-std=c++11 -O0
1
<Compilation failed>
x86-64 gcc 7.3 - 1737ms
#1 with x86-64 gcc 7.3
<source>: In function 'void _DOCTEST_ANON_TMP_8()':
<doctest/doctest.h>:2055:73: error: type/value mismatch at argument 1 in template parameter list for 'template<class T> struct doctest::detail::remove_const'
<doctest/doctest.h>:2099:58: note: in expansion of macro 'DOCTEST_ASSERT_THROWS_AS'
<source>:21:5: note: in expansion of macro 'DOCTEST_CHECK_THROWS_WITH_AS'
<doctest/doctest.h>:2055:73: note:   expected a type, got 'doctest::detail::remove_reference<typename T::out_of_range>::type'
<doctest/doctest.h>:2099:58: note: in expansion of macro 'DOCTEST_ASSERT_THROWS_AS'
<source>:21:5: note: in expansion of macro 'DOCTEST_CHECK_THROWS_WITH_AS'
<doctest/doctest.h>:2055:80: error: expected ')' before '&' token
<doctest/doctest.h>:2099:58: note: in expansion of macro 'DOCTEST_ASSERT_THROWS_AS'
<source>:21:5: note: in expansion of macro 'DOCTEST_CHECK_THROWS_WITH_AS'
<doctest/doctest.h>:2055:80: error: expected '{' before '&' token
<doctest/doctest.h>:2099:58: note: in expansion of macro 'DOCTEST_ASSERT_THROWS_AS'
<source>:21:5: note: in expansion of macro 'DOCTEST_CHECK_THROWS_WITH_AS'
<doctest/doctest.h>:2055:81: error: expected primary-expression before ')' token
<doctest/doctest.h>:2099:58: note: in expansion of macro 'DOCTEST_ASSERT_THROWS_AS'
<source>:21:5: note: in expansion of macro 'DOCTEST_CHECK_THROWS_WITH_AS'
<doctest/doctest.h>:2058:15: error: expected primary-expression before 'catch'
<doctest/doctest.h>:2099:58: note: in expansion of macro 'DOCTEST_ASSERT_THROWS_AS'
<source>:21:5: note: in expansion of macro 'DOCTEST_CHECK_THROWS_WITH_AS'

The workaround for this is quite straightforward:
https://godbolt.org/z/qWqxsr

#define DOCTEST_CONFIG_IMPLEMENT_WITH_MAIN
#include <https://raw.githubusercontent.com/onqtam/doctest/2.4.1/doctest/doctest.h>
#include <exception>

template<class T>
struct Json
{
    using out_of_range = std::out_of_range;

    T get()
    {
        throw out_of_range( "Out of range" );
        return T();
    }
};

#define DOCTEST_ASSERT_THROWS_AS_PATCHED(expr, assert_type, message, ...)                          \
    do {                                                                                           \
        if(!doctest::getContextOptions()->no_throw) {                                              \
            doctest::detail::ResultBuilder _DOCTEST_RB(doctest::assertType::assert_type, __FILE__, \
                                                       __LINE__, #expr, #__VA_ARGS__, message);    \
            try {                                                                                  \
                DOCTEST_CAST_TO_VOID(expr)                                                         \
            } catch(const typename doctest::detail::remove_const<                                  \
                    typename doctest::detail::remove_reference<__VA_ARGS__>::type>::type&) {       \
                _DOCTEST_RB.translateException();                                                  \
                _DOCTEST_RB.m_threw_as = true;                                                     \
            } catch(...) { _DOCTEST_RB.translateException(); }                                     \
            DOCTEST_ASSERT_LOG_AND_REACT(_DOCTEST_RB);                                             \
        }                                                                                          \
    } while(false)

#define DOCTEST_CHECK_THROWS_WITH_AS_PATCHED(expr, message, ...) DOCTEST_ASSERT_THROWS_AS_PATCHED(expr, DT_CHECK_THROWS_WITH_AS, message, __VA_ARGS__)


TEST_CASE_TEMPLATE("My testcase2", T,
                   Json<int>)
{
    T json;
    DOCTEST_CHECK_THROWS_WITH_AS_PATCHED(json.get(), "Out of range", typename T::out_of_range);
}

Need to add "typename" before both "doctest::detail::remove_const" and "doctest::detail::remove_reference". It seems not to harm even if the exception type is not dependant. But I'm not sure is it true for most of the compilers and c++ standards. At least such macro group could be added separately. Like DOCTEST_CHECK_THROWS_WITH_AS_DEPENDANT.

Extra information

• doctest version: v2.4.1
• Operating System: Godbolt
• Compiler+version: any

[onqtam]

adding typename doesn't seem to be a problem - pushing a fix for this in the dev branch - will release a new version by the end of December probably!