Search results
Results from the WOW.Com Content Network
In the C++ programming language, a reference is a simple reference datatype that is less powerful but safer than the pointer type inherited from C.The name C++ reference may cause confusion, as in computer science a reference is a general concept datatype, with pointers and C++ references being specific reference datatype implementations.
Since C++11, the C++ standard library also provides smart pointers (unique_ptr, shared_ptr and weak_ptr) which can be used in some situations as a safer alternative to primitive C pointers. C++ also supports another form of reference, quite different from a pointer, called simply a reference or reference type.
Format specifier Range Suffix for decimal constants bool: Boolean type, added in C23. 1 (exact) %d [false, true] — char: Smallest addressable unit of the machine that can contain basic character set. It is an integer type. Actual type can be either signed or unsigned. It contains CHAR_BIT bits. [3] ≥8 %c [CHAR_MIN, CHAR_MAX] — signed char
A reference is an abstract data type and may be implemented in many ways. Typically, a reference refers to data stored in memory on a given system, and its internal value is the memory address of the data, i.e. a reference is implemented as a pointer. For this reason a reference is often said to "point to" the data.
Many languages have explicit pointers or references. Reference types differ from these in that the entities they refer to are always accessed via references; for example, whereas in C++ it's possible to have either a std:: string and a std:: string *, where the former is a mutable string and the latter is an explicit pointer to a mutable string (unless it's a null pointer), in Java it is only ...
One commonly encountered difference is C being more weakly-typed regarding pointers. Specifically, C allows a void* pointer to be assigned to any pointer type without a cast, while C++ does not; this idiom appears often in C code using malloc memory allocation, [9] or in the passing of context pointers to the POSIX pthreads API, and other ...
On many common platforms, this use of pointer punning can create problems if different pointers are aligned in machine-specific ways. Furthermore, pointers of different sizes can alias accesses to the same memory, causing problems that are unchecked by the compiler. Even when data size and pointer representation match, however, compilers can ...
Even though C++ popularized the concept of smart pointers, especially the reference-counted variety, [3] the immediate predecessor of one of the languages that inspired C++'s design had reference-counted references built into the language. C++ was inspired in part by Simula67. [4] Simula67's ancestor was Simula I.