From 3005ac54ef738d118250cb2a5612347049ee992d Mon Sep 17 00:00:00 2001
From: Gabriel Ferreira <gabrielcarvfer@gmail.com>
Date: Sun, 7 Apr 2024 14:01:27 +0200
Subject: [PATCH] core: Allow bool<std::string> callback functions

---
 src/core/model/callback.h | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/src/core/model/callback.h b/src/core/model/callback.h
index f05e10407..8e3dafa8c 100644
--- a/src/core/model/callback.h
+++ b/src/core/model/callback.h
@@ -490,8 +490,10 @@ class Callback : public CallbackBase
      * of the first argument is a class derived from CallbackBase (i.e., a Callback).
      */
     template <typename T,
-              std::enable_if_t<!std::is_base_of_v<CallbackBase, T>, int> = 0,
-              typename... BArgs>
+              typename... BArgs,
+              std::enable_if_t<!std::is_base_of_v<CallbackBase, T> &&
+                                   std::is_invocable_r_v<R, T, BArgs..., UArgs...>,
+                               int> = 0>
     Callback(T func, BArgs... bargs)
     {
         // store the function in a std::function object