Constant toad_msg::msg::opt::known::repeat::IF_MATCH

pub const IF_MATCH: OptNumber;

If-Match

generated from RFC7252 section 5.10.8.1

The If-Match Option MAY be used to make a request conditional on the current existence or value of an ETag for one or more representations of the target resource. If-Match is generally useful for resource update requests, such as PUT requests, as a means for protecting against accidental overwrites when multiple clients are acting in parallel on the same resource (i.e., the “lost update” problem).

The value of an If-Match option is either an ETag or the empty string. An If-Match option with an ETag matches a representation with that exact ETag. An If-Match option with an empty value matches any existing representation (i.e., it places the precondition on the existence of any current representation for the target resource).

The If-Match Option can occur multiple times. If any of the options match, then the condition is fulfilled.

If there is one or more If-Match Options, but none of the options match, then the condition is not fulfilled.