From 80ddd9d5683b023e7ae20557118c839e59069d83 Mon Sep 17 00:00:00 2001
From: Linus Jahn <lnj@kaidan.im>
Date: Tue, 9 Aug 2022 14:36:47 +0200
Subject: FutureUtils: Add mapSuccess() to map success type of variants

---
 src/base/QXmppFutureUtils_p.h | 15 +++++++++++++++
 1 file changed, 15 insertions(+)

(limited to 'src/base')

diff --git a/src/base/QXmppFutureUtils_p.h b/src/base/QXmppFutureUtils_p.h
index bf8c2f35..2551be67 100644
--- a/src/base/QXmppFutureUtils_p.h
+++ b/src/base/QXmppFutureUtils_p.h
@@ -176,6 +176,21 @@ void reportFinishedResult(QFutureInterface<T> &interface, const T &result)
     interface.reportFinished();
 }
 
+template<typename T, typename Err, typename Function>
+auto mapSuccess(std::variant<T, Err> var, Function lambda)
+{
+    using MapResult = std::decay_t<decltype(lambda({}))>;
+    using MappedVariant = std::variant<MapResult, Err>;
+    return std::visit(overloaded {
+                          [lambda = std::move(lambda)](T val) -> MappedVariant {
+                              return lambda(std::move(val));
+                          },
+                          [](Err err) -> MappedVariant {
+                              return err;
+                          } },
+                      std::move(var));
+}
+
 }  // namespace QXmpp::Private
 
 #endif  // QXMPPFUTUREUTILS_P_H
-- 
cgit v1.2.3