Return true if a matching key exists

Synopsis

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

bool
contains(
    pct_string_view key,
    ignore_case_param ic = = {}) const noexcept;

Description

This function examines the parameters in the container to find a match for the specified key, which may contain percent escapes. The comparison is performed as if all escaped characters were decoded first.

Example

assert( url_view( "?first=John&last=Doe" ).encoded_params().contains( "first" ) );

Complexity

Linear in this->buffer().size().

Exception Safety

Exceptions thrown on invalid input.

Exceptions

Name Thrown on

system_error

key contains an invalid percent-encoding.

Parameters

Name Description

key

The key to match. By default, a case-sensitive comparison is used.

ic

An optional parameter. If the value ignore_case is passed here, the comparison is case-insensitive.