Set the host

Synopsis

Declared in header </boost/url/url_base.hpp#L921[boost/url/url_base.hpp,window=blank_]>

url_base&
set_host(string_view s);

Description

Depending on the contents of the passed string, this function sets the host:

  • If the string is a valid IPv4 address, then the host is set to the address. The host type is host_type::ipv4.

  • If the string is a valid IPv6 address enclosed in square brackets, then the host is set to that address. The host type is host_type::ipv6.

  • If the string is a valid IPvFuture address enclosed in square brackets, then the host is set to that address. The host type is host_type::ipvfuture.

  • Otherwise, the host name is set to the string, which may be empty. Reserved characters in the string are percent-escaped in the result. The host type is host_type::name. In all cases, when this function returns, the URL contains an authority.

Example

assert( url( "http://www.example.com" ).set_host( "127.0.0.1" ).buffer() == "http://127.0.0.1" );

Postconditions

this->has_authority() == true

Complexity

Linear in this->size() + s.size().

Exception Safety

Strong guarantee. Calls to allocate may throw.

BNF

host        = IP-literal / IPv4address / reg-name

IP-literal  = "[" ( IPv6address / IPvFuture  ) "]"

reg-name    = *( unreserved / pct-encoded / "-" / ".")

Specification

Return Value

  • ``

Parameters

Name Type

s

string_view