CMakeLists and elsewhere: require Qt 5.15

4 files changed, 10 insertions, 20 deletions

diff --git a/CMakeLists.txt b/CMakeLists.txt
index efdd5bb6..048d3b07 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -77,7 +77,7 @@ option(BUILD_WITH_QT6 "Build Quotient with Qt 6 (EXPERIMENTAL)" OFF)
 if (BUILD_WITH_QT6)
     set(QtMinVersion "6.0")
 else()
-    set(QtMinVersion "5.12")
+    set(QtMinVersion "5.15")
     set(QtExtraModules "Multimedia") # See #483
 endif()
 string(REGEX REPLACE "^(.).*" "Qt\\1" Qt ${QtMinVersion}) # makes "Qt5" or "Qt6"
diff --git a/CONTRIBUTING.md b/CONTRIBUTING.md
index bc65abf3..7a5ee079 100644
--- a/CONTRIBUTING.md
+++ b/CONTRIBUTING.md
@@ -154,14 +154,7 @@ just don't bankrupt us with it. Refactoring is welcome.
 
 ### Code style and formatting
 
-As of Quotient 0.7, the C++ standard for newly written code is C++20 with a few
-restrictions, notably:
-* enumerators and slots cannot have `[[attributes]]` because moc from Qt 5.12
-  chokes on them - this will be lifted when we move on to Qt 5.13 for the oldest
-  supported version, in the meantime use `Q_DECL_DEPRECATED` and similar Qt
-  macros - they expand to nothing when the code is passed to moc.
-* explicit lists in lambda captures are preferred over `[=]`; note that C++20
-  deprecates implicit `this` capture in `[=]`.
+As of Quotient 0.7, the C++ standard for newly written code is C++20.
 
 The code style is defined by `.clang-format`, and in general, all C++ files
 should follow it. Files with minor deviations from the defined style are still
diff --git a/README.md b/README.md
index e42cb488..2deaa28b 100644
--- a/README.md
+++ b/README.md
@@ -26,19 +26,17 @@ If you find what looks like a security issue, please use instructions
 in SECURITY.md.
 
 ## Getting and using libQuotient
-Depending on your platform, the library can come as a separate package.
-Recent releases of Debian and openSUSE, e.g., already have the package
-(under the old name). If your Linux repo doesn't provide binary package
-(either libqmatrixclient - older - or libquotient - newer), or you're
-on Windows or macOS, your best bet is to build the library from the source
-and bundle it with your application.
+Depending on your platform, the library can be obtained from a package
+management system. Recent releases of Debian and openSUSE, e.g., already have
+it. Alternatively, just build the library from the source and bundle it with
+your application, as described below.
 
 ### Pre-requisites
 - A recent Linux, macOS or Windows system (desktop versions are known to work;
   mobile operating systems where Qt is available might work too)
-  - Recent enough Linux examples: Debian Bullseye; Fedora 33; openSUSE Leap 15.3;
-    Ubuntu Focal Fossa.
-- Qt 5 (either Open Source or Commercial), 5.12 or higher
+  - Recent enough Linux examples: Debian Bullseye; Fedora 35;
+    openSUSE Leap 15.4; Ubuntu 22.04 LTS.
+- Qt 5 (either Open Source or Commercial), 5.15 or higher
 - CMake 3.16 or newer (from your package management system or
   [the official website](https://cmake.org/download/))
 - A C++ toolchain with that supports at least some subset of C++20:
diff --git a/libquotient.pri b/libquotient.pri
index 677f60d3..1b4bd9c0 100644
--- a/libquotient.pri
+++ b/libquotient.pri
@@ -1,8 +1,7 @@
 QT += network multimedia
 QT -= gui
 
-# TODO: Having moved to Qt 5.12, replace c++1z with c++17 below
-CONFIG *= c++1z warn_on rtti_off create_prl object_parallel_to_source
+CONFIG *= c++20 warn_on rtti_off create_prl object_parallel_to_source
 
 win32-msvc* {
     # Quotient code base does not play well with NMake inference rules