From: Kornelius Kalnbach <murphy@...>
Date: 2010-03-05T01:37:13+09:00
Subject: [ruby-core:28474] Re: [Feature #905] Add String.new(fixnum) to 	preallocate large buffer

Doesn't Ruby allocate already using a "double memory if you run out"
rule? That makes string concatenation (amortized) linear, even if the
string must be moved in the memory.

I doubt that there are real-world use cases that would be much faster
with preallocation. As Yusuke said, ERb is more of a counter-example.

Even with this API extension, we wouldn't have control over the
generation of the string buffer in many use cases, as in Array#join,
String#% or in literals using #{}. Its use would be limited to String#<<.

[murphy]