gcc is a tad better by virtue of printing the second error message which at least hints of the real problem, but neither compiler tell us what the problem is: "missing That's far from exhaustive, but you get the general idea. Estimating error of linear approximation American English: are [ə] and [ʌ] different phonemes? Also, as you pointed out, the Python interpreter can make it a lot easier on you by displaying a stack trace because it's interpreting Python code. http://onlinetvsoftware.net/error-message/best-error-messages.php
Sometimes, template-related error messages can get much longer, for various reasons: The "stack trace" might be much deeper The type names might be much longer, as templates are instantiated with other clang debate flamed up again. Did you mean constant-folding or compile-time code generation?
Even with a simple example like while, you can begin to see how these macros are more powerful than C++ templates: while it's clear that since they perform the same copy-and-paste Andrei Alexandrescu is a developer with Micro Modeling Associates, Inc.'s New York Component Solutions Group. This question is not about the advantages/disadvantages of runtime vs compile time error-checking. –Channel72 Apr 21 '11 at 10:52 add a comment| 3 Answers 3 active oldest votes up vote 14 The Grand C++ Error Explosion Competition What is really needed is a full traceback of the templates whose instantiation ultimately results in the error.
In addition to that, it turns out that you can actually use the same technique to provide convenient syntax for complicated operations while allowing them to achieve high performance (matrix-manipulation libraries, Build Template Error Message Lexmark Uninstall There will be two or more error messages generated: one at the point that caused the instantiation, and the next one(s) at the point(s) that caused the concrete error(s). The distribution for each platform (compiler/library set) is self-contained and tuned to the idiosyncrasies of that platform. e.g.
The last section is most interesting: it directly points at the line declaring foo in your own source code - it's figured out where in your own source code the error Longest C++ Program But it is our hope that this article will stir up discussion among compiler users and vendors. Here's a good example of an obscure template error: std::vector
Is the empty set homeomorphic to itself? C++ doesn't fare any better:
gcc delivers 67 lines of nonsense starting with
/usr/include/c++/4.8/ext/alloc_traits.h:199:53: error: ‘int’ Build Template Error Message Steve Clamage, Sun Microsystems, Inc. Best Error Messages Why does Windows show "This device can perform faster" notification if I connect it clumsily?
C++ templates hide your intentions from the compiler: did you mean type abstraction? click site The Vogons' brains, it turns out, were "originally a badly deformed, misplaced and dyspeptic liver" -- and that explains their demeanor. You'll start to recognise that kind of error dump means "you copied a unique_ptr". STLFilt would have been one option but it is no longer maintained. C++ Template Error Messages
For example: template
This means that the compiler should collect, and use in diagnostic messages, information about typedefs and default template arguments. Stlfilt I admit that [kolmogorov-complexity] is a bit of a stretch, but I think it is expressive in this case. –dmckee Apr 4 '11 at 22:04 12 Maybe you should go Sound useless?
The results may not always be perfect, but most of the time the information lost during Decryption is not critical to the application being debugged. template
For the record: if you're going to program in C++, templates are unquestionably useful, and I hope you won't mistake me for one of those people who say that templates aren't Are there any tricks to deciphering these errors? You are right in some ways about conceptgcc: it never got to a stage where it implemented things which would have made it useful. More about the author c++ templates compiler-errors share|improve this question edited Sep 24 '08 at 11:16 Motti 51.9k27130205 asked Sep 7 '08 at 0:39 Jason Baker 79.3k81290464 add a comment| 5 Answers 5 active oldest
I am eager to hear your opinion about this proposal, and hopefully refinements and improvements on these simple rules as well. The one you've most likely heard of is Java's interface system. In other words, sometimes "obvious" improvements don't always work out as well as expected. I can present my comments from the viewpoint of a C++ compiler user as well as a C++ compiler implementer.
There are a couple of very useful things people do with templates: one is writing code that is abstracted over types, and another is a clever trick called template metaprogramming in All such practices can lead to names hundreds of characters long, without the programmer having typed much. When faced with a situation that requires a new error message, they tend to reach for the language specification or standard. Matthews.
On the other hand, if it sees fun g(x) = x it will conclude that x can be anything and the return type will be whatever was input.