boost::urls::params_ref

A view representing query parameters in a URL

Synopsis

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

class params_ref
    : public params_base;

Types

Name

Description

const_iterator

A Bidirectional iterator to a query parameter

const_reference

The reference type

difference_type

A signed integer type used to represent differences.

iterator

A Bidirectional iterator to a query parameter

reference

The reference type

size_type

An unsigned integer type to represent sizes.

value_type

The value type

Member Functions

Name

Description

append

Append elements

assign

Assign elements

begin

Return an iterator to the beginning

buffer

Return the referenced character buffer.

clear

Clear the contents of the container

contains

Return true if a matching key exists

count

Return the number of matching keys

empty

Return true if there are no params

end

Return an iterator to the end

Erase elements

Find a matching key

Find a matching key

Insert elements

operator params_view

Conversion

operator=

Assignment

params_ref [constructor]

Constructor

replace

Replace elements

set

Set a value

size

Return the number of params

unset

Remove the value on an element

url

Return the referenced url

Static Member Functions

Name

Description

max_size

Return the maximum number of characters possible

Description

Objects of this type are used to interpret the query parameters as a bidirectional view of key/value pairs. The view does not retain ownership of the elements and instead references the original url. The caller is responsible for ensuring that the lifetime of the referenced url extends until it is no longer referenced. The view is modifiable; calling non-const members causes changes to the referenced url.

Percent escapes in strings returned when dereferencing iterators are automatically decoded. Reserved characters in strings supplied to modifier functions are automatically percent-escaped.

Example

url u( "?first=John&last=Doe" );

params_ref p = u.params();

Iterator Invalidation

Changes to the underlying character buffer can invalidate iterators which reference it. Modifications made through the container invalidate some or all iterators:

append : Only end().
assign , clear , operator= : All elements.
erase : Erased elements and all elements after (including end()).
insert : All elements at or after the insertion point (including end()).
replace , set : Modified elements and all elements after (including end()).