Default values to bitfield elements
bit-fields, c++, c++11
Solution
No, bit-fields do not allow an initializer as part of the member declaration. You can see this in the part of the grammar that describes class members (C++11 and later, [class.mem]):
member-declarator: declarator virt-specifier-seqopt pure-specifieropt declarator brace-or-equal-initializeropt identifieropt attribute-specifier-seqopt : constant-expression
The third form is the grammar for a bit-field declaration, but only the second form lists the brace-or-equal-initializer.
Problem
In C++11 one can do ``` struct S {int i = 42;}; ``` and if one forgets to initialize the member `i` it gets default initialized to 42. I Just tried this with bitfields as ``` struct S {int i = 42 : 5;}; ``` and am getting error: expected ';' before ':' token Does this feature exist for bitfield members and if so, how do I use it?