GL: this internal API always takes a C string anyway.

src/Magnum/GL/Context.h

@@ -662,7 +662,7 @@ class MAGNUM_GL_EXPORT Context {
     #ifdef DOXYGEN_GENERATING_OUTPUT
     private:
     #endif
-        bool isDriverWorkaroundDisabled(const std::string& workaround);
+        bool isDriverWorkaroundDisabled(const char* workaround);
         Implementation::State& state() { return *_state; }
 
         /* This function is called from MeshState constructor, which means the

src/Magnum/GL/Implementation/driverSpecific.cpp

@@ -364,7 +364,7 @@ void Context::disableDriverWorkaround(const std::string& workaround) {
     _driverWorkarounds.emplace_back(workaround, true);
 }
 
-bool Context::isDriverWorkaroundDisabled(const std::string& workaround) {
+bool Context::isDriverWorkaroundDisabled(const char* workaround) {
     CORRADE_INTERNAL_ASSERT(std::find(KnownWorkarounds.begin(), KnownWorkarounds.end(), workaround) != KnownWorkarounds.end());
 
     /* If the workaround was already asked for or disabled, return its state,