Search results
Results From The WOW.Com Content Network
// A class template to express an equality comparison interface. template < typename T > class equal_comparable {friend bool operator == (T const & a, T const & b) {return a. equal_to (b);} friend bool operator!= (T const & a, T const & b) {return! a. equal_to (b);}}; // Class value_type wants to have == and !=, so it derives from // equal_comparable with itself as argument (which is the CRTP ...
Most C code can easily be made to compile correctly in C++ but there are a few differences that cause some valid C code to be invalid or behave differently in C++. For example, C allows implicit conversion from void * to other pointer types but C++ does not (for type safety reasons).
A common example is iostream in C++, where for example << returns the left object, allowing chaining. Compare: a << b << c; equivalent to: a << b; a << c;
Since exceptions in C++ are supposed to be exceptional (i.e. uncommon/rare) events, the phrase "zero-cost exceptions" [note 2] is sometimes used to describe exception handling in C++. Like runtime type identification (RTTI), exceptions might not adhere to C++'s zero-overhead principle as implementing exception handling at run-time requires a ...
C and C++ distinguish implementation-defined behavior from unspecified behavior. For implementation-defined behavior, the implementation must choose a particular behavior and document it. An example in C/C++ is the size of integer data types. The choice of behavior must be consistent with the documented behavior within a given execution of the ...
Each assignment to a Vec, such as Vec x = a + b + c, generates a new Vec constructor if needed by template instantiation. This constructor operates on three Vec; it allocates the necessary memory and then performs the computation. Thus only one memory allocation is performed. Example implementation of expression templates :
The C standard library, sometimes referred to as libc, [1] is the standard library for the C programming language, as specified in the ISO C standard. [2] Starting from the original ANSI C standard, it was developed at the same time as the C POSIX library, which is a superset of it. [3]
In C/C++, it is possible to declare the parameter of a function or method as constant. This is a guarantee that this parameter cannot be inadvertently modified after its initialization by the caller. If the parameter is a pre-defined (built-in) type, it is called by value and cannot be modified.