Nothing like this exists in the C or C++ standards at present. In fact, there isn’t even a guarantee that float will be a binary floating-point format at all. Some compilers guarantee that the float type will be the IEEE-754 32 bit binary format. Some do not. In reality, float is in fact the IEEE-754 … Read more
I found myself disagreeing with the highest-voted answer, so I went looking for expert opinons and here they are. From http://channel9.msdn.com/Shows/Going+Deep/C-and-Beyond-2011-Scott-Andrei-and-Herb-Ask-Us-Anything Herb Sutter: “when you pass shared_ptrs, copies are expensive” Scott Meyers: “There’s nothing special about shared_ptr when it comes to whether you pass it by value, or pass it by reference. Use exactly the … Read more
Are you sure you are doing it the correct way? The idea is that CMake sets BOOST_INCLUDE_DIR, BOOST_LIBRARYDIR and BOOST_ROOT automatically. Do something like this in CMakeLists.txt: FIND_PACKAGE(Boost) IF (Boost_FOUND) INCLUDE_DIRECTORIES(${Boost_INCLUDE_DIR}) ADD_DEFINITIONS( “-DHAS_BOOST” ) ENDIF() If boost is not installed in a default location and can, thus, not be found by CMake, you can tell … Read more
The boost library you are using depends on the boost_system library. (Not all of them do.) Assuming you use gcc, try adding -lboost_system to your compiler command line in order to link against that library.
There is a straightforward algorithm for picking an item at random, where items have individual weights: 1) calculate the sum of all the weights 2) pick a random number that is 0 or greater and is less than the sum of the weights 3) go through the items one at a time, subtracting their weight … Read more
Probably the most used part of boost for me is boost::shared_ptr.
1800 INFORMATION is more or less correct, but there are a few issues I wanted to correct. boost::shared_mutex _access; void reader() { boost::shared_lock< boost::shared_mutex > lock(_access); // do work here, without anyone having exclusive access } void conditional_writer() { boost::upgrade_lock< boost::shared_mutex > lock(_access); // do work here, without anyone having exclusive access if (something) { … Read more
As a short answer: bjam –toolset=msvc-9.0 address-model=64 –build-type=complete As a longer answer, here are my build notes for having VS .NET 2008 32-bit and 64-bit boost libraries in the same hierarchy (which is I suspect a common use case): Build the win32 binaries bjam –toolset=msvc-9.0 –build-type=complete stage Create the directory lib\win32 Move the contents of … Read more
The implementation of a non-specialized template must be visible to a translation unit that uses it. The compiler must be able to see the implementation in order to generate code for all specializations in your code. This can be achieved in two ways: 1) Move the implementation inside the header. 2) If you want to … Read more
You can use dynamic_pointer_cast. It is supported by std::shared_ptr. std::shared_ptr<Base> base (new Derived()); std::shared_ptr<Derived> derived = std::dynamic_pointer_cast<Derived> (base); Documentation: https://en.cppreference.com/w/cpp/memory/shared_ptr/pointer_cast Also, I don’t recommend using cast operator in the base class. Implicit casting like this may become the source of bugs and errors. -Update: If the type is not polymorphic, std::static_pointer_cast may be used.