Called once to fully initialize the object before any calls to `put`. The message body is valid before entering this function, and remains valid until the reader is destroyed. The value of `n` will be set to the content length of the body if known, otherwise `n` will be equal to `boost::none`. Implementations of [*BodyReader] may use this information to optimize allocation. The function will ensure that `!ec` is `true` if there was no error or set to the appropriate error code if there was one.
Called once to fully initialize the object before any calls to `put`. The message body is valid before entering this function, and remains valid until the reader is destroyed. The value of `n` will be set to the content length of the body if known, otherwise `n` will be equal to `boost::none`. Implementations of [*BodyReader] may use this information to optimize allocation. The function will ensure that `!ec` is `true` if there was no error or set to the appropriate error code if there was one.
The function will ensure that `!ec` is `true` if there was no error or set to the appropriate error code if there was one.
The function will ensure that `!ec` is `true` if there was no error or set to the appropriate error code if there was one.