At least this compiles and works:
#include <iostream>
#include <memory>
#include <string>
template <class T>
std::shared_ptr<T> make_instance();
template <class T> requires std::is_default_constructible_v<T>
std::shared_ptr<T> make_instance()
{
return std::make_shared<T>();
}
When I switched to PHP 7.4 I forgot to specify sendmail_path parameter in php.ini and my contact form stopped working. Today I found sendmail_path parameter in PHP 7.0:
cd /etc/php
find . -name "php.ini"
./7.0/fpm/php.ini
./7.0/cgi/php.ini
./7.0/cli/php.ini
./7.4/fpm/php.ini
./7.4/cli/php.ini
grep sendmail ./7.0/fpm/php.ini
sendmail_path = "/usr/sbin/sendmail -t -f *****@yandex.ru -i"
I build it with similar commands as I used before for Building QT 6.3.1 with OpenSSL for Windows. The only difference was that I added -static-runtime option and skipped qtquick3dphysics and qtspeech modules:
"C:\Program Files\Microsoft Visual Studio\2022\Professional\VC\Auxiliary\Build\vcvarsall.bat" amd64
set "CMAKE_ROOT=C:\dev\PFiles\cmake-3.24.0-rc4-windows-x86_64\bin"
set "NINJA_ROOT=C:\dev\PFiles\ninja-win"
set "PERL_ROOT=C:\dev\PFiles\Strawberry\perl\bin"
set PATH=%CMAKE_ROOT%;%PATH%
set PATH=%NINJA_ROOT%;%PATH%
set PATH=%PERL_ROOT%;%PATH%
set PATH=C:\dev\PFiles\Python35;%PATH%
rem Check if the tools are in PATH
where perl.exe
where python.exe
where cmake.exe
where ninja.exe
set "MY_INSTALL_PATH=C:/dev/libs/Qt6.4/windows"
set CL=/MP
configure.bat -prefix %MY_INSTALL_PATH% -DQT_NO_EXCEPTIONS=1 -debug-and-release -force-debug-info -platform win32-msvc -opensource -confirm-license ^
-c++std c++20 -static -static-runtime -I "C:/Program Files/OpenSSL/include" -L "C:/Program Files/OpenSSL/lib" -openssl-linked ^
-skip qt3d -skip qt5compat -skip qtactiveqt -skip qtcharts -skip qtcoap -skip qtconnectivity ^
-skip qtdatavis3d -skip qtdoc -skip qtlottie -skip qtmqtt -skip qtnetworkauth -skip qtopcua ^
-skip qtserialport -skip qtpositioning -skip qtquicktimeline -skip qtquick3d -skip qtremoteobjects ^
-skip qtscxml -skip qtsensors -skip qtserialbus -skip qtvirtualkeyboard -skip qtwayland ^
-skip qtwebchannel -skip qtwebengine -skip qtwebview -skip qttools -skip qttranslations -skip qtquick3dphysics -skip qtspeech
Source file:
soxi short-borrowed-old.wav
Input File : 'short-borrowed-old.wav' (flac)
Channels : 2
Sample Rate : 44100
Precision : 16-bit
Duration : 00:00:00.60 = 26460 samples = 45 CDDA sectors
File Size : 54.0k
Bit Rate : 720k
Sample Encoding: 16-bit FLAC
Comment : 'Comment=Processed by SoX'
There is no difference between lines 82 and 92 in the code below with both MSVC2022 and GCC11:
#include <utility>
#include <stdexcept>
#include <iostream>
struct Object
{
virtual const char* name() = 0;
virtual ~Object() = default;
};
struct A : public Object
{
const char* name() override
{
return "A";
}
};
QT is developed by an alien civilization that hate humans. They can’t make std::shared_ptr work in QML since 2014:
It converts only from non-virtual base class subobject:
struct B
{
virtual ~B() {};
};
struct D : public virtual B { };
int main()
{
D d;
B& br1 = d;
// cannot convert a 'B*' to a 'D*'; conversion from a virtual base class is implied
// static_cast<D&>(br1);
dynamic_cast<D&>(br1);
return 0;
}
In the vernacular they say stack and heap, but the standard call this automatic and dynamic:
In my previous post I compared the performance of a single QT connection with the performance of a notification mechanism based on virtual functions.
In this post I’ll demonstrate how the performance of QT signals degrade when the number of the connections grow. Briefly saying a QT signal becomes 57 times slower than a virtual function.
Below I described my experimentations and provided the full source code.
(more…)