From d4e62a9768c4ce4964f65cca15b3da0a36b910f1 Mon Sep 17 00:00:00 2001
From: Marc Mutz <marc.mutz@qt.io>
Date: Fri, 7 Oct 2022 16:50:42 +0200
Subject: Short live q20::transform()!
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

It just adds constexpr to it (we're ignoring the range version).

Apply it to QOffsetStringArray, where it replaces the copyData()
function.

Pick-to: 6.4
Change-Id: I6caf3b5fd2e60f4fcb0b116684c3ad6a8043f38e
Reviewed-by: Mårten Nordheim <marten.nordheim@qt.io>
---
 src/corelib/tools/qoffsetstringarray_p.h | 14 +++-----------
 1 file changed, 3 insertions(+), 11 deletions(-)

(limited to 'src/corelib/tools/qoffsetstringarray_p.h')

diff --git a/src/corelib/tools/qoffsetstringarray_p.h b/src/corelib/tools/qoffsetstringarray_p.h
index 4083487175..2a0e6de55b 100644
--- a/src/corelib/tools/qoffsetstringarray_p.h
+++ b/src/corelib/tools/qoffsetstringarray_p.h
@@ -70,16 +70,6 @@ private:
 };
 
 namespace QtPrivate {
-// std::copy is not constexpr in C++17
-template <typename II, typename OO>
-static constexpr OO copyData(II input, qsizetype n, OO output)
-{
-    using E = decltype(+*output);
-    for (qsizetype i = 0; i < n; ++i)
-        output[i] = E(input[i]);
-    return output + n;
-}
-
 template <size_t Highest> constexpr auto minifyValue()
 {
     if constexpr (Highest <= (std::numeric_limits<quint8>::max)()) {
@@ -137,7 +127,9 @@ constexpr auto makeOffsetStringArray(StringExtractor extractString, const T &...
 
     // prepend zero
     std::array<MinifiedOffsetType, Count + 1> minifiedOffsetList = {};
-    QtPrivate::copyData(fullOffsetList.begin(), Count, minifiedOffsetList.begin() + 1);
+    q20::transform(fullOffsetList.begin(), fullOffsetList.end(),
+                   minifiedOffsetList.begin() + 1,
+                   [] (auto e) { return MinifiedOffsetType(e); });
 
     std::array staticString = QtPrivate::makeStaticString<StringLength>(extractString, entries...);
     return QOffsetStringArray(staticString, minifiedOffsetList);
-- 
cgit v1.2.3