C++11 - User-defined literals

C++11 standard provides new way of customized literal constants called user defined literals. Thanks to that user can define own suffixes for standard literals (ex. digits) which defines it better and makes it better readable. Example of such suffixes could be: _meters, _kilograms, _squareMeters etc.

For better understanding user-defined literals concept, let's take a look on the below example code: Output of that code is: In point one we can see concept of operator overloading function which should be used in order to define user-defined literals. In our example we are defining suffixex _meters and _squareMeters which will be used for imporve readability of code of calculations based on that units.

Point II shows how we can use user-defined literals to assign values to variables. Such usage definitely makes code better readable and easier to understand.

Point III, shows how we can use other suffix (_squareMeters) in comparison calculations. As we can see, our units are logically used the same way as normal number literals. However, (thanks to user-defined literals) we can easely understand which units are used in particular case.

Points III and IV, shows how user-defined literals are used in printing its values into console. We can see that values printed from our literals are the same as its numerical values.

Code of above example can be found on our github account: https://github.com/xmementoit/CppAdventureExamples/tree/master/cpp11/userDefinedLiterals

Comments

GDB Automatic Deadlock Detector

Have you ever had a problem with detection deadlock between threads in your C/C++ application? Would you like to do that automatically? Try this GDB Automatic Deadlock Detector from my github: GDB Automatic Deadlock Detector Picture source: http://csunplugged.org/wp-content/uploads/2015/03/deadlock.jpg1286488735

STL - count and count_if algorithms

One of the basic and most useful STL algorithms is algorithm which can be used to count number of elements within selected container according to specified criteria. In order to do that we can use std::count or std::count_if algorithm. std::count (firstElementIterator, lastElementIterator, elementForSearch) - is function which will go through container using firstElementIterator and lastElementIterator and return number of container elements which value is equal elementForSearch std::count_if (firstElementIterator, lastElementIterator, UnaryPredicateFunction) - is function which examine range from firstElementIterator to lastElementIterator and return number of container elements which fulfill UnaryPredicateFunction criteria. UnaryPredicateFunction is function having following signature: bool functionName(const Type& a) . So, count_if returns number of elements where UnaryPredicateFunction returns true for. For better understanding let's take a

Advanced C++ - Stack unwinding

Stack unwinding is normally a concept of removing function entries from call stack (also known as Execution stack, Control stack, Function stack or Run-time stack). Call Stack is a stack data structure that stores active functions' addresses and helps in supporting function call/return mechanism. Every time when a function is called, an entry is made into Call stack which contains the return address of the calling function where the control needs to return after the execution of called function. This entry is called by various names like stack frame , activation frame or activation record. With respect to exception handling , stack Unwinding is a process of linearly searching function call stack to reach exception handler. When an exception occurs, if it is not handled in current function where it is thrown, the function Call Stack is unwound until the control reaches try block and then passes to catch block at the end of try block to handle exception. Also, in this proc

Developer Adventure

Search This Blog