Boost C++ Libraries

...one of the most highly regarded and expertly designed C++ library projects in the world. Herb Sutter and Andrei Alexandrescu, C++ Coding Standards

This is the documentation for a snapshot of the master branch, built from commit 9fc5439165.
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params_view

A view representing query parameters in a URL.

Synopsis

Defined in header <boost/url/params_view.hpp>

class params_view :
    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

begin

Return an iterator to the beginning.

buffer

Return the referenced character buffer.

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.

find

Find a matching key.

find_last

Find a matching key.

operator=

Assignment.

params_view [constructor]

Constructor.

size

Return the number of params.

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 character buffer. The caller is responsible for ensuring that the lifetime of the buffer extends until it is no longer referenced.

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

params_view p = u.params();

The strings produced when iterators are dereferenced belong to the iterator and become invalidated when that particular iterator is incremented, decremented, or destroyed. Any percent-escapes in returned strings are decoded first. Strings passed to member functions do not contain percent-escapes; the percent character ('') is treated as a literal percent.

Iterator Invalidation

Changes to the underlying character buffer can invalidate iterators which reference it.

Convenience header <boost/url.hpp>


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