22 General utilities library [utilities]

22.14 Formatting [format]

22.14.2 Format string [format.string] Standard format specifiers [format.string.std]

Table 74: Meaning of type options for bool[tab:format.type.bool]
none, s
Copies textual representation, either true or false, to the output.
b, B, d, o, x, X
As specified in Table 72 for the value static_cast<unsigned char>(value).