#Help needed trying to figure out if derived class overrides an overloaded virtual method.

15 messages · Page 1 of 1 (latest)

frail root
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Hey, I'm working on an event-based plugin system for my application and I'd need to know if certain event handlers are overridden so I can determine whether they need to be called or not.

So here's an simplified version of my problem https://godbolt.org/z/WEWd7Gd9v and I'm kind of stuck to be honest. If anyone could help it would be greatly appreciated 😄

Compiler Explorer - C++

struct SomeEventA {};
struct SomeEventB {};

struct PluginBase {
virtual void onEvent(SomeEventA& e) { printf("SomeEventA intact!\n");}
virtual void onEvent(SomeEventB& e) { printf("SomeEventB intact!\n");}
};

struct Foo : PluginBase {
using PluginBase::onEvent;

void onEvent(SomeEventA& e) override { printf("SomeEventA override...
teal parrotBOT
#

When your question is answered use !solved to mark the question as resolved.

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frail root
#

oh shit I did an oopsie when simplifying my problem

#

bool overridesEvent(PluginBase* pPlugin) {

is supposed to be

bool overridesEvent(auto* pPlugin) {

#

Then it should be using PluginDerived = typename std::remove_pointer_t<decltype(pPlugin)>;

#

I had remove_reference_t because I was passing a reference to a pointer at some point

#

There still might be other small quirks like that but honestly I'm not thinking straight rn, it's 2am for me

drowsy zenith
#

do it tommororw.

frail root
#

I ended up doing this monstrosity https://godbolt.org/z/sdzGPoa6h

Compiler Explorer - C++

struct SomeEventA {};
struct SomeEventB {};

struct PluginBase {
virtual void onEvent(SomeEventA& e) { printf("SomeEventA intact!\n");}
virtual void onEvent(SomeEventB& e) { printf("SomeEventB intact!\n");}
};

struct Foo : PluginBase {
using PluginBase::onEvent;

void onEvent(SomeEventA& e) override { printf("SomeEventA override...
#

I figure out the index where the virtual function is located in the vtable, then I compare the function address from that vtable from the real instance with a base one

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I'm not so confident it should work on all compilers, but at this point I don't really care and just want it to compile and work using Clang

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Well unless if someone has a better idea

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!solved for now

teal parrotBOT
frail root
#

!solved