Shift suppression to code

Author: eacousineau

.travis.yml

@@ -186,8 +186,6 @@ install:
 
     if [ "$CLANG" = "7" ]; then
       export CXXFLAGS="-stdlib=libc++"
-      # Suppress this warning b/c it's inherent to how `py::self` is used for overloads
-      export CXXFLAGS="$CXXFLAGS -Wno-self-assign-overloaded"
     fi
 
     export NPY_NUM_BUILD_JOBS=2

tests/test_operator_overloading.cpp

@@ -62,6 +62,23 @@ namespace std {
     };
 }
 
+#pragma GCC diagnostic push
+// clang 7.0.0 and Apple LLVM 10.0.1 introduce `-Wself-assign-overloaded` to
+// `-Wall`, which is used here for overloading (e.g. `py::self += py::self `).
+// Here, we suppress the warning using `#pragma diagnostic`.
+// Taken from: https://github.com/RobotLocomotion/drake/commit/aaf84b46
+// TODO(eric): This could be resolved using a function / functor (e.g. `py::self()`).
+#if (__clang__) && (__APPLE__)
+  #if (__clang_major__ >= 10) && (__clang_minor__ >= 0) && (__clang_patchlevel__ >= 1)
+    #pragma GCC diagnostic ignored "-Wself-assign-overloaded"
+  #endif
+#elif (__clang__)
+  #if (__clang_major__ >= 7)
+    #pragma GCC diagnostic ignored "-Wself-assign-overloaded"
+  #endif
+#endif
+#endif
+
 TEST_SUBMODULE(operators, m) {
 
     // test_operator_overloading
@@ -144,3 +161,5 @@ TEST_SUBMODULE(operators, m) {
         .def_readwrite("b", &NestC::b);
     m.def("get_NestC", [](const NestC &c) { return c.value; });
 }
+
+#pragma GCC diagnostic pop