rust-lang/rust — pull request #16201 by erickt (2014-08-02 16:57:04+00:00)
Title: serialize: add json::{Integer,Floating} to parse large integers properly

This patch allows json to deserialize integers larger than 2^53 without losing precision. It does this by first keeping the integer portion of a number as a `i64`, and only casting it over to a `f64` if we have a decimal or exponent.