[#boost-urls-url_view_base-host_ipv4_address]
= xref:boost/urls/url_view_base/host_ipv4_address.adoc[boost::urls::url_view_base::host_ipv4_address]
:relfileprefix: ../../../
:mrdocs:

Return the host IPv4 address

== Synopsis

Declared in `<https://www.github.com/boostorg/url/blob/develop/include/boost/url/url_view_base.hpp#L1260[boost/url/url_view_base.hpp]>`

[source,cpp,subs="verbatim,replacements,macros,-callouts"]
----
xref:boost/urls/ipv4_address.adoc[ipv4_address]
host_ipv4_address() const noexcept;
----

== Description

If the host type is xref:boost/urls/host_type.adoc[`host_type::ipv4`], this function returns the address as a value of type xref:boost/urls/ipv4_address.adoc[`ipv4_address`]. Otherwise, if the host type is not an IPv4 address, it returns a default‐constructed value which is equal to the unspecified address "0.0.0.0".

== Example
[,cpp]
----
assert( url_view( "http://127.0.0.1/index.htm?user=win95" ).host_ipv4_address() == ipv4_address( "127.0.0.1" ) );
----
== Complexity
Constant.

== Exception Safety
Throws nothing.

== BNF
[,cpp]
----
IPv4address = dec-octet "." dec-octet "." dec-octet "." dec-octet

dec-octet   = DIGIT                 ; 0-9
            / %x31-39 DIGIT         ; 10-99
            / "1" 2DIGIT            ; 100-199
            / "2" %x30-34 DIGIT     ; 200-249
            / "25" %x30-35          ; 250-255
----
== Specification
* https://datatracker.ietf.org/doc/html/rfc3986#section-3.2.2[]

== Return Value

The IPv4 address as a value of type xref:boost/urls/ipv4_address.adoc[`ipv4_address`].


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