gcc considers some Call memfn ambiguous

[daedric]

No description provided.

[jfirebaugh]

What's the error you're getting for this, what code triggers it, and what GCC version are you using? With GCC 5.4.1, I get a linker error ("symbol `_ZL6method' is already defined") compiling the tests, which I guess is not related.

[daedric]

I tested with gcc 5 and 6 with my current master it works, with mapbox's I've those errors:

/Users/daedric/work/perso/jni.hpp/examples/hello.cpp: In lambda function:
/Users/daedric/work/perso/jni.hpp/examples/hello.cpp:57:105: error: call of overloaded 'Call(JNIEnv&, jni::Method<RegisterHighLevel(JavaVM*)::PrintStream, void(jni::Object<jni::StringTag>)>&, jni::Object<jni::StringTag>)' is ambiguous
                 u"Hello, " + jni::Make<std::u16string>(env, args.Get(env, 0)) + u" (Native High-Level)"));
                                                                                                         ^
In file included from /Users/daedric/work/perso/jni.hpp/include/jni/jni.hpp:13:0,
                 from /Users/daedric/work/perso/jni.hpp/examples/hello.cpp:1:
/Users/daedric/work/perso/jni.hpp/include/jni/object.hpp:108:18: note: candidate: std::enable_if_t<(! jni::IsPrimitive<T>::value), T> jni::Object<TheTag>::Call(JNIEnv&, const jni::Method<TheTag, R(Args ...)>&, const Args& ...) const [with R = void; Args = {jni::Object<jni::StringTag>}; TheTag = RegisterHighLevel(JavaVM*)::PrintStream; std::enable_if_t<(! jni::IsPrimitive<T>::value), T> = void; JNIEnv = JNIEnv_]
             auto Call(JNIEnv& env, const Method<TagType, R (Args...)>& method, const Args&... args) const
                  ^~~~
/Users/daedric/work/perso/jni.hpp/include/jni/object.hpp:115:18: note: candidate: void jni::Object<TheTag>::Call(JNIEnv&, const jni::Method<TheTag, void(Args ...)>&, const Args& ...) const [[ 57%] Built target hello_jar
with Args = {jni::Object<jni::StringTag>}; TheTag = RegisterHighLevel(JavaVM*)::PrintStream; JNIEnv = JNIEnv_]
             void Call(JNIEnv& env, const Method<TagType, void (Args...)>& method, const Args&... args) const
                  ^~~~
/Users/daedric/work/perso/jni.hpp/test/high_level.cpp: In function 'int main()':
/Users/daedric/work/perso/jni.hpp/test/high_level.cpp:409:63: error: call of overloaded 'Call(TestEnv&, jni::StaticMethod<{anonymous}::Test, void(unsigned char)>&, const jboolean&)' is ambiguous
     testClass.Call(env, voidBooleanStaticMethod, jni::jni_true);
                                                               ^
In file included from /Users/daedric/work/perso/jni.hpp/include/jni/jni.hpp:12:0,
                 from /Users/daedric/work/perso/jni.hpp/test/high_level.cpp:3:
/Users/daedric/work/perso/jni.hpp/include/jni/class.hpp:92:18: note: candidate: std::enable_if_t<(! jni::IsPrimitive<T>::value), T> jni::Class<TheTag>::Call(JNIEnv&, const jni::StaticMethod<TheTag, R(Args ...)>&, const Args& ...) const [with R = void; Args = {unsigned char}; TheTag = {anonymous}::Test; std::enable_if_t<(! jni::IsPrimitive<T>::value), T> = void; JNIEnv = _JNIEnv]
             auto Call(JNIEnv& env, const StaticMethod<TagType, R (Args...)>& method, const Args&... args) const
                  ^~~~
/Users/daedric/work/perso/jni.hpp/include/jni/class.hpp:99:18: note: candidate: void jni::Class<TheTag>::Call(JNIEnv&, const jni::StaticMethod<TheTag, void(Args ...)>&, const Args& ...) const [with Args = {unsigned char}; TheTag = {anonymous}::Test; JNIEnv = _JNIEnv]
             void Call(JNIEnv& env, const StaticMethod<TagType, void (Args...)>& method, const Args&... args) const
                  ^~~~
/Users/daedric/work/perso/jni.hpp/test/high_level.cpp:410:55: error: call of overloaded 'Call(TestEnv&, jni::StaticMethod<{anonymous}::Test, void(jni::Object<{anonymous}::Test>)>&, jni::Object<{anonymous}::Test>&)' is ambiguous
     testClass.Call(env, voidObjectStaticMethod, object);
                                                       ^
In file included from /Users/daedric/work/perso/jni.hpp/include/jni/jni.hpp:12:0,
                 from /Users/daedric/work/perso/jni.hpp/test/high_level.cpp:3:
/Users/daedric/work/perso/jni.hpp/include/jni/class.hpp:92:18: note: candidate: std::enable_if_t<(! jni::IsPrimitive<T>::value), T> jni::Class<TheTag>::Call(JNIEnv&, const jni::StaticMethod<TheTag, R(Args ...)>&, const Args& ...) const [with R = void; Args = {jni::Object<{anonymous}::Test>}; TheTag = {anonymous}::Test; std::enable_if_t<(! jni::IsPrimitive<T>::value), T> = void; JNIEnv = _JNIEnv]
             auto Call(JNIEnv& env, const StaticMethod<TagType, R (Args...)>& method, const Args&... args) const
                  ^~~~
/Users/daedric/work/perso/jni.hpp/include/jni/class.hpp:99:18: note: candidate: void jni::Class<TheTag>::Call(JNIEnv&, const jni::StaticMethod<TheTag, void(Args ...)>&, const Args& ...) const [with Args = {jni::Object<{anonymous}::Test>}; TheTag = {anonymous}::Test; JNIEnv = _JNIEnv]
             void Call(JNIEnv& env, const StaticMethod<TagType, void (Args...)>& method, const Args&... args) const
                  ^~~~
/Users/daedric/work/perso/jni.hpp/test/high_level.cpp:509:54: error: call of overloaded 'Call(TestEnv&, jni::Method<{anonymous}::Test, void(unsigned char)>&, const jboolean&)' is ambiguous
     object.Call(env, voidBooleanMethod, jni::jni_true);
                                                      ^
In file included from /Users/daedric/work/perso/jni.hpp/include/jni/jni.hpp:13:0,
                 from /Users/daedric/work/perso/jni.hpp/test/high_level.cpp:3:
/Users/daedric/work/perso/jni.hpp/include/jni/object.hpp:108:18: note: candidate: std::enable_if_t<(! jni::IsPrimitive<T>::value), T> jni::Object<TheTag>::Call(JNIEnv&, const jni::Method<TheTag, R(Args ...)>&, const Args& ...) const [with R = void; Args = {unsigned char}; TheTag = {anonymous}::Test; std::enable_if_t<(! jni::IsPrimitive<T>::value), T> = void; JNIEnv = _JNIEnv]
             auto Call(JNIEnv& env, const Method<TagType, R (Args...)>& method, const Args&... args) const
                  ^~~~
/Users/daedric/work/perso/jni.hpp/include/jni/object.hpp:115:18: note: candidate: void jni::Object<TheTag>::Call(JNIEnv&, const jni::Method<TheTag, void(Args ...)>&, const Args& ...) const [with Args = {unsigned char}; TheTag = {anonymous}::Test; JNIEnv = _JNIEnv]
             void Call(JNIEnv& env, const Method<TagType, void (Args...)>& method, const Args&... args) const
                  ^~~~
/Users/daedric/work/perso/jni.hpp/test/high_level.cpp:510:46: error: call of overloaded 'Call(TestEnv&, jni::Method<{anonymous}::Test, void(jni::Object<{anonymous}::Test>)>&, jni::Object<{anonymous}::Test>&)' is ambiguous
     object.Call(env, voidObjectMethod, object);
                                              ^
In file included from /Users/daedric/work/perso/jni.hpp/include/jni/jni.hpp:13:0,
                 from /Users/daedric/work/perso/jni.hpp/test/high_level.cpp:3:
/Users/daedric/work/perso/jni.hpp/include/jni/object.hpp:108:18: note: candidate: std::enable_if_t<(! jni::IsPrimitive<T>::value), T> jni::Object<TheTag>::Call(JNIEnv&, const jni::Method<TheTag, R(Args ...)>&, const Args& ...) const [with R = void; Args = {jni::Object<{anonymous}::Test>}; TheTag = {anonymous}::Test; std::enable_if_t<(! jni::IsPrimitive<T>::value), T> = void; JNIEnv = _JNIEnv]
             auto Call(JNIEnv& env, const Method<TagType, R (Args...)>& method, const Args&... args) const
                  ^~~~
/Users/daedric/work/perso/jni.hpp/include/jni/object.hpp:115:18: note: candidate: void jni::Object<TheTag>::Call(JNIEnv&, const jni::Method<TheTag, void(Args ...)>&, const Args& ...) const [with Args = {jni::Object<{anonymous}::Test>}; TheTag = {anonymous}::Test; JNIEnv = _JNIEnv]
             void Call(JNIEnv& env, const Method<TagType, void (Args...)>& method, const Args&... args) const
                  ^~~~

[jfirebaugh]

Thanks. Reduced testcase: https://godbolt.org/g/9PqHZh

I tried to submit a GCC bug, but their bugtracker is closed to new account creation. ☹️

[jfirebaugh]

Applied in 69a84f7. Thanks again!

[daedric]

I've an account there, I'll submit one and link the issue :)

[daedric]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=80679

Thanks