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During the 10 years I used C++ I never saw a project that used std::string as their standard string. The implementation of std::string not standardized. It may

During the 10 years I used C++ I never saw a project that used std::string as their standard string. The implementation of std::string not standardized. It may or may not have a 'small string optimization' which may not be an optimization at all. Instead of specifying a mundane immutable built-in string like in Java the C++ Standards committee decided to add even more 'advanced' features to an already overloaded language.

richardwhiuk 12y ago
Heh, as if Java's string was mundane, or even particularly well standardised. The implementation for String have varied in each of the JVM versions, and Android has a different version to the JDK. Java's string, depending on the string, length, JVM version and a bunch of other factors may or may not: - Be interned - so the result of "str1" == "str1" is compiler dependant (you must do "str1".equals("str1")). - Maintain references to the string when doing a substring - e.g. "Java is a language full of quirks......".substring(0,4) may or may not hold a reference to the entire string. This has huge performance tradeoffs - e.g. if you parse JSON by doing .substring(), and aren't careful, then you can end up holding onto the entire unparsed JSON, even if you only keep track of a single obejct.
- kjetil 12y ago
  Are you seriously suggesting that String incompatibilites are a big issues in Java? String interning is specified in the JLS: http://docs.oracle.com/javase/specs/jls/se8/html/jls-3.html#jls-3.10.5 http://docs.oracle.com/javase/specs/jls/se8/html/jls-3.html#... As far as I can tell, the substring "feature" has been there since Java 1.0 and was fixed in Java 7. Hardly groundbreaking stuff.
csl 12y ago
The interface and behavior of std::string is standardized. Library writers are free to implement it in any way that honors the standard. However, sometimes the requirements may lead to less than optimal implementations, I believe. So as long as Chrome uses std::string for internal use only, there shouldn't be any problems. Using them across ABI boundaries, however, is another story.

richardwhiuk 12y ago

Heh, as if Java's string was mundane, or even particularly well standardised. The implementation for String have varied in each of the JVM versions, and Android has a different version to the JDK. Java's string, depending on the string, length, JVM version and a bunch of other factors may or may not: - Be interned - so the result of "str1" == "str1" is compiler dependant (you must do "str1".equals("str1")). - Maintain references to the string when doing a substring - e.g. "Java is a language full of quirks......".substring(0,4) may or may not hold a reference to the entire string. This has huge performance tradeoffs - e.g. if you parse JSON by doing .substring(), and aren't careful, then you can end up holding onto the entire unparsed JSON, even if you only keep track of a single obejct.

kjetil 12y ago
Are you seriously suggesting that String incompatibilites are a big issues in Java? String interning is specified in the JLS: http://docs.oracle.com/javase/specs/jls/se8/html/jls-3.html#jls-3.10.5 http://docs.oracle.com/javase/specs/jls/se8/html/jls-3.html#... As far as I can tell, the substring "feature" has been there since Java 1.0 and was fixed in Java 7. Hardly groundbreaking stuff.

csl 12y ago

The interface and behavior of std::string is standardized. Library writers are free to implement it in any way that honors the standard. However, sometimes the requirements may lead to less than optimal implementations, I believe. So as long as Chrome uses std::string for internal use only, there shouldn't be any problems. Using them across ABI boundaries, however, is another story.