From 16c6db608f1d04233e62e38005e9614f23862054 Mon Sep 17 00:00:00 2001
From: Thomas Spriggs <thomas.spriggs@diffblue.com>
Date: Tue, 14 Nov 2023 17:53:51 +0000
Subject: [PATCH 1/2] Remove explicit return type of the `ranget::map` function

Because infering the return type from the template parameters is a
sizeable portion of the function implementation. So using an `auto` type
tells the compiler that the type is in the return statement and saves us
duplicating the same work in two places.
---
 src/util/range.h | 4 +---
 1 file changed, 1 insertion(+), 3 deletions(-)

diff --git a/src/util/range.h b/src/util/range.h
index c714cdb0464..023b169503a 100644
--- a/src/util/range.h
+++ b/src/util/range.h
@@ -418,9 +418,7 @@ struct ranget final
   /// a value through `f`. `f` may take a move-only typed parameter by const
   /// reference. 'f' may also construct and return a move-only typed value.
   template <typename functiont>
-  auto map(functiont &&f) -> ranget<map_iteratort<
-    iteratort,
-    typename std::result_of<functiont(value_type)>::type>>
+  auto map(functiont &&f)
   {
     using outputt = typename std::result_of<functiont(value_type)>::type;
     auto shared_f = std::make_shared<

From bd69bdbc5df0c9d06b5fa9663f056ee6d4d84a70 Mon Sep 17 00:00:00 2001
From: Thomas Spriggs <thomas.spriggs@diffblue.com>
Date: Tue, 14 Nov 2023 17:57:41 +0000
Subject: [PATCH 2/2] Replace usage of `std::result_of` with
 `std::invoke_result`

C++17 deprecates `std::result_of` in favour of `std::invoke_result`.
Updating our code to use the replacement avoids the use of the
reprecated version.
---
 src/util/range.h | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/util/range.h b/src/util/range.h
index 023b169503a..d884e7635fe 100644
--- a/src/util/range.h
+++ b/src/util/range.h
@@ -420,7 +420,7 @@ struct ranget final
   template <typename functiont>
   auto map(functiont &&f)
   {
-    using outputt = typename std::result_of<functiont(value_type)>::type;
+    using outputt = typename std::invoke_result<functiont, value_type>::type;
     auto shared_f = std::make_shared<
       std::function<outputt(const typename iteratort::value_type &)>>(
       std::forward<functiont>(f));