boost::urls::params_ref

Mutable decoded query parameter proxy

Synopsis

Declared in <boost/url/params_ref.hpp>

class params_ref
    : public params_base

Description

This container presents the decoded query parameters of a url_base as a bidirectional range whose modifying operations update the underlying URL in‐place. It references (but does not own) the character buffer, so the referenced URL must stay alive while the proxy is used.

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()`).

Reads vs. writes

Although this is a mutable proxy, all observer helpers inherited from params_base (such as contains, find, and get_or) operate in the same way as they do on params_view: they perform their lookup against the current contents of the referenced URL without modifying it.