A query parameter

Synopsis

Declared in header <boost/url/param.hpp>

struct param;

Member Functions

Name

Description

operator→

operator=

Assignment

param [constructor]

Constructor

Data Members

Name

Description

has_value

True if a value is present

key

The key

value

The value

Description

Objects of this type represent a single key and value pair in a query string where a key is always present and may be empty, while the presence of a value is indicated by has_value equal to true. An empty value is distinct from no value.

Depending on where the object was obtained, the strings may or may not contain percent escapes.

For most usages, key comparisons are case-sensitive and duplicate keys in a query are possible. However, it is the authority that has final control over how the query is interpreted.

BNF

query-params    = query-param *( "&" query-param )
query-param     = key [ "=" value ]
key             = *qpchar
value           = *( qpchar / "=" )

Specification

See Also

param_view , param_pct_view .