C++ Cookbook

Introduction

This chapter describes solutions to some common requirements when internationalizing C++ programs. Making software work in different locales (usually referred to as localization) usually requires solving two problems: formatting user-visible strings such that they obey local conventions (such as those for date, time, money, and numbers), and reconciling data in different character sets. This chapter deals mostly with the first issue, and only briefly with the second, because there is little standardized support for different character sets since most aspects of it are largely implementation dependent.

Most software will also run in countries other than the one where it was written. To support this practical reality, the C++ standard library has several facilities for writing code that will run in different countries. The design of these facilities, however, is different than many other standard library facilities such as strings, file input and output, containers, algorithms, and so forth. For example, the class that is used to represent a locale is locale, and is provided in the <locale> header. locale provides facilities for writing to and reading from streams using locale-specific formatting, and for getting information about a locale, such as the currency symbol or the date format. The standard only requires that a single locale be provided though, and that is the “C” or classic locale. The classic locale uses ANSI C conventions: American English conventions and ...