boost::urls::params_ref

A view representing query parameters in a URL

Synopsis

Declared in <include/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`	Erase elements
`find`	Find a matching key
`find_last`	Find a matching key
`insert`	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.


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

params_ref p = u.params();

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()`).