Afaik, there are only two approaches that are compliant with strict aliasing rules: memcpy() and cast to char* with copying. All others read a float from memory that belongs to an uint32_t, and the compiler is allowed to perform the read before the write to that memory location. It might even optimize away the write … Read more
Unless you have a specific requirement to work with XML 1.1 (which is very rare), you should read the XML 1.0 Recommendation. Tim Bray, one of the original editors of the specification, has created an excellent annotated version of it which you can find at http://www.xml.com/axml/axml.html For a bit more info/opinion on XML 1.1, check … Read more
This was fixed about a month ago (for gcc 4.7.0). The bug report makes for an interesting read: http://gcc.gnu.org/bugzilla/show_bug.cgi?id=1773
According to RFC 2396, Appendix A: scheme = alpha *( alpha | digit | “+” | “-” | “.” ) Meaning: The scheme should start with a letter (upper or lower case), and can contains letters (still upper and lower case), number, “+”, “-” and “.”. Note: in the case of paparazzi:http:[//<host>[:[<port>][<transport>]]/ the scheme is … Read more
Both (a) and (b) result in undefined behavior. It’s always undefined behavior to call a member function through a null pointer. If the function is static, it’s technically undefined as well, but there’s some dispute. The first thing to understand is why it’s undefined behavior to dereference a null pointer. In C++03, there’s actually a … Read more
A. It is not valid HTML nor XHTML In the official W3C XHTML specification, Section B. “Element Prohibitions”, states that: “form must not contain other form elements.” http://www.w3.org/TR/xhtml1/#prohibitions As for the older HTML 3.2 spec, the section on the FORMS element states that: “Every form must be enclosed within a FORM element. There can be … Read more
<> should be preferred, all things being equal, since it accords with the sql standard and is technically more portable… != is non-standard, but most db’s implement it. sql:2008 grammar: <not equals operator> ::= <>
Clause 9 of the standard allows class {public: int i;} (note the lack of a final semicolon) because this decl-specifier-seq for an unnamed class might be used in some other construct such as a typedef or a variable declaration. The problem with class {public: int i;}; (note that the final semicolon is now present) is … Read more
If you want to write portable C code, then I’d suggest you to write in C89 (old ANSI C standard). This standard is supported by most compilers. The Intel C Compiler has very good C99 support and it produces fast binaries. (Thanks 0x69!) MSVC supports some new features and Microsoft plan to broaden support in … Read more
The answer is no, because of the definition of “lifetime” in §3.8/1: The lifetime of an object of type T ends when: — if T is a class type with a non-trivial destructor (12.4), the destructor call starts, or — the storage which the object occupies is reused or released. As soon as the destructor … Read more