[expr.or]

The | operator groups left-to-right.

The operands shall be of integral or unscoped enumeration type.

The usual arithmetic conversions ([expr.arith.conv]) are performed.

Given the coefficients

x_{i}

and

y_{i}

of the base-2 representation ([basic.fundamental]) of the converted operands x and y, the coefficient

r_{i}

of the base-2 representation of the result r is 1 if at least one of

x_{i}

and

y_{i}

are 1, and 0 otherwise.

The result is the bitwise inclusive OR function of the operands.

— end note

]

7 Expressions [expr]