Issue #13251 has been updated by Nobuyoshi Nakada.

Status changed from Open to Assigned
Backport changed from 2.2: UNKNOWN, 2.3: UNKNOWN, 2.4: UNKNOWN to 2.2: DONTNEED, 2.3: DONTNEED, 2.4: DONTNEED

Thank you, feel free to add it.

I was writing it too, but you'll make better one.
This is my draft, FYI.

```diff
diff --git c/NEWS i/NEWS
index 2a0413f006..8647e5e2ce 100644
--- c/NEWS
+++ i/NEWS
@@ -21,4 +21,8 @@ with all sufficient information, see the ChangeLog file or Redmine
 === Core classes updates (outstanding ones only)
 
+* Integer
+
+  * Integer.sqrt  [Feature #13219]
+
 * Regexp
   * Update Onigmo 6.1.1.
	Modified   numeric.c
diff --git c/numeric.c i/numeric.c
index b34fb0a5f9..c827a8c7c9 100644
--- c/numeric.c
+++ i/numeric.c
@@ -5155,4 +5155,22 @@ DEFINE_INT_SQRT(BDIGIT, rb_bdigit_dbl, BDIGIT_DBL)
 VALUE rb_big_isqrt(VALUE);
 
+/*
+ *  call-seq:
+ *     Integer.sqrt(x)  ->  Integer
+ *
+ *  Returns the largest integer which does not exceed the non-negative
+ *  square root of _x_.  Equivalent to `Math.sqrt(x).floor`, except
+ *  for that the result of the latter code may be greater than the
+ *  true root when _x_ exceeds the Float precision.
+ *
+ *  If _x_ is not an Integer, it is converted to an Integer first.
+ *  If _x_ is negative, a Math::DomainError is raised, as well as
+ *  Math.sqrt.
+ *
+ *     Integer.sqrt(0)        #=> 0
+ *     Integer.sqrt(1)        #=> 1
+ *     Integer.sqrt(10)       #=> 3
+ *     Integer.sqrt(10**400)  #=> 10**200
+ */
 static VALUE
 rb_int_s_isqrt(VALUE self, VALUE num)

```

----------------------------------------
Bug #13251: [DOC] Add rdoc for Integer.sqrt
https://bugs.ruby-lang.org/issues/13251#change-63195

* Author: Marcus Stollsteimer
* Status: Assigned
* Priority: Normal
* Assignee: Marcus Stollsteimer
* Target version: 
* ruby -v: ruby 2.5.0dev (2017-02-24 trunk 57707) [x86_64-linux]
* Backport: 2.2: DONTNEED, 2.3: DONTNEED, 2.4: DONTNEED
----------------------------------------
Nobu, I would offer to add documentation for Integer.sqrt, feature #13219 (r57705).

I'd like to prepare a patch and eventually try to commit it myself.

I'm not sure yet when to open issues for documentation and when to simply commit; I would be glad about any feedback.



-- 
https://bugs.ruby-lang.org/

Unsubscribe: <mailto:ruby-core-request / ruby-lang.org?subject=unsubscribe>
<http://lists.ruby-lang.org/cgi-bin/mailman/options/ruby-core>