This is my review of the Boost Locale library. It is divided into two parts, a review of the documentation and a review of the library itself. I will refer to Boost Locale as just Locale, with a capital L, for the remainder of this review. I will use the term C++ locale to refer to the C++ standard library locale implementation. 1. Documentation The layout of the main page is decent, but I would have expected a discussion there, or as a first topic, of what Locale brings that the C++ standard locale does not have. I was disappointed not to find such a discussion. The documentation topics are specified as Tutorials. I do not think they are Tutorials, which is fine with me since I much prefer topics rather than exmaples when trying to understand a library. a. Introduction to C++ Standard Library localization support The common critical problems of the C++ locale portion of the standard library seems spurious to me. The problems mentioned are really about implementations or programmer usage, not the C++ locale library itself. The only valid problem mentioned I find there is that the C++ standard library did not attempt to standardize any locale names. This makes using C++ locales based on locale names non-portable. Unfortunately the issues there make a very weak argument for the Locale library itself. b. Locale generation I would have liked it if the doc here specified where one finds valid lists of language, country, encoding, and variant which make up a locale name. Without this information, the one valid problem mentioned regarding C++ locale is also a problem with Locale. The note about wide strings and 8-bit encoding makes no sense to me at all. If I am using a wide string encoding, why would I not be using wide string iostreams ? c. Collation There is no explanation about what 'collation' is about. This is very disappointing, as it makes the rest of the discussion difficult to follow. The examples were worthless to me since the classes involved have not been mentioned or discussed. Also the examples are woefully incomplete even in what they represent. This is one reason why I dislike documentation which attempts to teach by example. It always seems to assume that if it throws examples at the reader before anything about the classes/templates in the examples have been mentioned, that this is somehow an effective way of learning a library. Instead it just creates confusion and serves unfortunately as a way by which a library implementer does not have to explain how the classes in his library actually work or relate to each other. d. Conversions "You may notice that there are existing functions to_upper and to_lower in the Boost.StringAlgo library. The difference is that these function operate over an entire string instead of performing incorrect character-by-character conversions." In he second sentence, "these function" gramatically refers to the functions in Boost.StringAlgo, but I doubt that is what is meant. I do not understand how these conversion functions use a locale. The example gives: boost::locale::to_upper(gruben) used in a stream. Is this function using the locale imbued in the iostream ? Again this is what happens when one creates examples without first explaining topics in a rational and orderly way. e. Numbers, Time and Currency formatting and parsing A bunch of ICU flags are mentioned but with no indication about how these are supposed to be used by iostreams. These flags look like they are supposed to be used by C-like format printf statements but since Locale uses iostreams I can not understand their purpose with Locale. f. Messages Formatting (Translation) Gnu gettext should be explained when it interfaces with Locale. Just telling someone to learn Gnu gettext is not adequate. Other than that the explanation is pretty thorough. g. Character Set Conversions An explanation of what character sets are, and what character set conversions entail, should be the beginning of this documentation. h. Localized Text Formatting "Each format specifier is enclosed within {} brackets.." These are not "brackets" but "braces". Brackets are '[]'. i. In general It is confusing to me how generated locales affect the functionality of the different sections presented under 'Using Boost.Locale'. In a number of situations I am looking at classes or functions and I have no idea how these pick up a locale. I do understand that when used with iostreams the locale is determined by the locale imbued in the iostream. But outside of iostreams I do not understand from the documentation what locale is being used. If it is the C++ global locale, the documentation should say so. This entire issue about how locales are actually being used in various parts of the library should be explained as part of an overall explanation of the library. I find this good overall explanation of the library the major flaw in the documentation. The documentation itself is well-ordered and the explanations generally decent. But I find it next to impossible to understand a library when the documentation does not take the time to explain concepts/topics and instead substititutes exmaples as a means of understaning a library. 2. Library itself I did not look at the code itself and have no interest in critiquing the source. Others do this much better than I ever can. The library offers a great deal of functionality and a great positive of the library is that it works with multiple backends and brings those backends into the C++ world. In general I think that using the global locale is a bad programming practice when one specifically intends to work with locales. Unfortunately it was hard for me to understand how individual locales are used with each of the parts of the library from the documentation. But I will assume for the time being, because it seems the only correct design, that each part of the library which is documented can work with some non-global locale which is created and passed around as necessary. The only design flaw which I could discover in the library was in message translation. The fact that translation always begin from English ( or perhaps some other narrow character language ) to something else is horrendous. I can understand that the Locale implementer wanted to use something popular and that already exists, but an idea so tremendously flawed in its conception either needs to be changed, if possible, or discarded for something better. I do understand that translation is just one part of this large library, but I hope that the implementer undestands how ridiculous it is to assume that non-English programmers are going to be willing to translate from English to language X rather than from their own language to language X. I am assuming that all other parts of the library support both narrow character encodings and wide character encodings fully, and that at least UTF-16 is always supported using wide characters. It was really hard for me to make out from the docs whether or not this was the case. I believe a great deal of work was put into the library, and that this work is invaluable in bringing locale usage into C++ in a better way than it is currently supported in C++ locale. But I would have to vote "No" that the library should be accepted into Boost at the current time, with some provisos which would most likely gain my own change to a "Yes" vote in the future. 1) The documentation should explain the differences and improvements of Locale over C++ locale in a good general way. 2) The documentation should explain the use of locales for each of the topics. 3) A number of topics should discuss what they are about in general, and more time should be given to discuss how the classes/templates relate to each other. 4) Message translation should be reconsidered. I don't mean to say that the way it is done is enough to have the library rejected, but I can not believe that it is not a flawed system no matter what the popularity of Gnu gettext might be. My major trouble with the library, which has led to my "No" vote, is that I can not really understand how to use the library from the documentation or what the library really offers over and above C++ locales. I realize the library programmer may not himself be a native English speaker, but if I can not really understand a library from its documentation in a way that makes sense to me I can not vote for its inclusion into Boost. I strongly suspect that if I were to understand the functionality of the library through a more rigorous explanation of its topics, and each topics relationship to a locale class and various encodings, I mught well vote for its inclusion into Boost. But for now, and in the state which the documentation resides for me, I can not do so. So I hope this review will be undersstood at least partially as a request to improve the docs as much as anything else.