cpp/error/system error/system error

Constructs new system error object.

@1@ Constructs with error code @2@ Constructs with error code and explanation string. The string returned by what is guaranteed to contain as a substring. @3@ Constructs with underlying error code and associated error category. @4@ Constructs with underlying error code, associated error category and explanatory string. The string returned by what is guaranteed to contain as a substring (assuming that it doesn't contain an embedded null character ). @5@ Copy constructor. Initializes the contents with those of. If and  both have dynamic type  then.