Logical operators cppreference com

بواسطةNada Sabaneh

When target-expr is a bit-field that cannot represent the value of the expression, the resulting value of the bit-field is implementation-defined. These pointer arithmetic operators allow pointers to satisfy the LegacyRandomAccessIterator requirements. All built-in arithmetic operators compute the result of specific arithmetic operation and returns its result.

Built-in bitwise logic operators

Copy assignment replaces the contents of the object a with a copy of the contents of b (b is not modified). For class types, this is performed in a special member function, described in copy assignment operator. For the binary operators (except shifts), if the promoted operands have different types, usual arithmetic conversions are applied. If the operand passed to a built-in arithmetic operator is integral or unscoped enumeration type, then before any other action (but after lvalue-to-rvalue conversion, if applicable), the operand undergoes integral promotion. If an operand has array or function type, array-to-pointer and function-to-pointer conversions are applied. For built-in multiplication and division operators, both operands must have arithmetic or unscoped enumeration type.

  • In the remaining description in this section, “operand(s)”, lhs and rhs refer to the converted operand(s).
  • For the binary operators (except shifts), if the promoted operands have different types, usual arithmetic conversions are applied.
  • The object referred to by target-expr is modified by replacing its value with the result of new-value.
  • Note that bitwise logic operators do not perform short-circuiting.
  • If new-value is an expression, it is implicitly converted tothe cv-unqualified type of target-expr.
  • If an operand has array or function type, array-to-pointer and function-to-pointer conversions are applied.

Unrelated to contracting, intermediate results of floating-point arithmetic may have range and precision that is different from the one indicated by its type, see FLT_EVAL_METHOD. For the built-in logical NOT operator, the result is true if the operand is false.

Assignment operators

For the built-in bitwise NOT operator, rhs must be a prvalue of integral or unscoped enumeration type, and integral promotion is performed on rhs. For other built-in bitwise logic operators, both operands must have integral or unscoped enumeration type, and usual arithmetic conversions are performed on both operands. For the built-in bitwise shift operators, both operands must be prvalues of integral or unscoped enumeration type. Move assignment replaces the contents of the object a with the contents of b, avoiding copying if possible (b may be modified). For class types, this is performed in a special member function, described in move assignment operator.

Built-in simple assignment operator

  • Unsigned integer arithmetic is always performed modulo 2n where n is the number of bits in that particular integer.
  • For non-class types, copy and move assignment are indistinguishable and are referred to as direct assignment.
  • Move assignment replaces the contents of the object a with the contents of b, avoiding copying if possible (b may be modified).
  • E.g. for unsigned int, adding one to UINT_MAX gives ​0​, and subtracting one from ​0​ gives UINT_MAX.

The following behavior-changing defect reports were applied retroactively to previously published C++ standards. Compound assignment replace the contents of the object a with the result of a binary operation between the previous value of a and the value of b. The namespace std is used to place names of xor neural network the standard C++ library.

The name posix is reserved for a future top-level namespace. The behavior is undefined if a program declares or defines anything in that namespace. In the remaining description in this section, “operand(s)”, lhs and rhs refer to the converted operand(s).

Logical operators

See Extending namespace std for the rules about adding names to it. Atomically replaces the current value with the result of bitwise XOR of the value and arg. Where LRx is the result of usual arithmetic conversions on Lx and Rx. Where LR is the result of usual arithmetic conversions on L and R. Formally, the C++ standard makes no guarantee on the accuracy of floating-point operations.

Additive operators

In the remaining description in this section, “operand(s)”, a, b, lhs and rhs refer to the converted or promoted operand(s). In the remaining description in this section, “operand(s)”, lhs and rhs refer to the converted or promoted operand(s). Unsigned integer arithmetic is always performed modulo 2n where n is the number of bits in that particular integer. E.g. for unsigned int, adding one to UINT_MAX gives ​0​, and subtracting one from ​0​ gives UINT_MAX. The object referred to by target-expr is modified by replacing its value with the result of new-value. If new-value is not an expression, the assignment expression will never match an overloaded compound assignment operator.

Multi-character operators and punctuators

For the built-in remainder operator, both operands must have integral or unscoped enumeration type. Usual arithmetic conversions are performed on both operands. If the value of rhs is negative or is not less than the number of bits in lhs, the behavior is undefined. If the type of target-expr is volatile-qualified, the assignment is deprecated, unless the (possibly parenthesized) assignment expression is a discarded-value expression or an unevaluated operand. If new-value is an expression, it is implicitly converted tothe cv-unqualified type of target-expr.

Note that bitwise logic operators do not perform short-circuiting. The result of a built-in simple assignment is an lvalue of the type of target-expr, referring to target-expr. If target-expr is a bit-field, the result is also a bit-field. For non-class types, copy and move assignment are indistinguishable and are referred to as direct assignment. When an expression J that has integral type is added to or subtracted from an expression P of pointer type, the result has the type of P.

std::atomic::fetch_xor

If target-expr and new-value identify overlapping objects, the behavior is undefined (unless the overlap is exact and the type is the same). In addition to keywords, there are identifiers with special meaning, which may be used as names of objects or functions, but have special meaning in certain contexts. Arithmetic operators are overloaded for many standard library types.