View source for Template:Size

<includeonly>{{#vardefine:page|{{{1}}}}}{{#vardefine:minindex|0}}{{#vardefine:maxindex|1}}<!--
Find the upper bound of the size in steps of 2^n
-->{{#while:
|{{{{#var:page}}|{{#var:maxindex}}}}
|{{#vardefine:minindex|{{#var:maxindex}}}}{{Multiply|maxindex|2}}
}}{{#vardefine:index|{{#expr:floor(({{#var:maxindex}}+{{#var:minindex}})/2)}}}}<!--
Perform a binary search between [2^n-1, 2^n] to find the last element of the list
-->{{#while:
|{{#ifexpr:{{#var:minindex}}+1<{{#var:maxindex}}|true}}
|
{{#if:{{{{#var:page}}|{{#var:index}}}}
<!--undershoot-->|{{#vardefine:minindex|{{#var:index}}}}
<!-- overshoot-->|{{#vardefine:maxindex|{{#var:index}}}}
}}
{{#vardefine:index|{{#expr:floor(({{#var:maxindex}}+{{#var:minindex}})/2)}}}}
}}{{#var:index}}</includeonly><noinclude>
{{Template doc|
Get size of a list given a template that maps index -> entry.

Largely deprecated by [[Template:List lookup helper|List lookup helper]].

<pre>
{{Size|Quick links lingo}}

{{Size|Anecdote}}
</pre>

{{Size|Quick links lingo}}

{{Size|Anecdote}}
}}</noinclude>