I believe I have found the relevant piece of standardese. §14.8.2p7 says: The substitution occurs in all types and expressions that are used in the function type and in template parameter declarations. Since EnableIf<dependent_true_type<T>> is used in a template parameter declaration, substitution should occur and this is a bug in clang.
See http://gcc.gnu.org/bugzilla/show_bug.cgi?id=37428 and also http://gcc.gnu.org/bugzilla/show_bug.cgi?id=42121 Yes, it’s weird.
Yes, that is valid C++. One purpose i’ve found for it is to translate exceptions into return values, and have the code translating the exceptions in return values separate from the other code in the function. Yes, you can return x; from a catch block like the one you showed (i’ve only recently discovered that, … Read more
The members of a standard container have to be copy assignable or movable (C++11). If the type is const it fails the requirements.
GCC’s -Weffc++ has several issues, I never use it. The code that checks for “problems” is pretty simplistic and so the warnings end up being far too blunt and unhelpful. That particular warning is based on Item 11 of the first edition of Effective C++ and Scott changed it (for the better) in later editions. … Read more
When using -l<libname> to specify library to link, the linker will first search for lib<libname>.so before searching for lib<libname>.a. In your case it doesn’t work, because the library filename is not with .so suffix. You may create simlink libbeat.so -> libbeat.so.1.0.1 or libbeat.so -> libbeat.so.1 libbeat.so.1 -> libbeat.so.1.0.1 You can also use -l:libbeat.so.1.0.1 (if your … Read more
$ gcc -Wconversion test.c test.c: In function ‘main’: test.c:3: warning: conversion to ‘int’ from ‘double’ may alter its value
This is a bug in gcc 4.8 that has been fixed in 4.9. Here is the bug report: https://gcc.gnu.org/bugzilla/show_bug.cgi?id=50025
If we look at the libstdc++ status we see that they do have support for the File System TS: Paper | Title | Status …….. N4100 | File System | Y but it says: This page describes the C++14 and library TS support in mainline GCC SVN, not in any particular release. and from trying … Read more
Yes, it is ill-formed. Here’s why: A constexpr function needs to be defined (not just declared) before being used in a constant expression. So for example: constexpr int f(); // declare f constexpr int x = f(); // use f – ILLEGAL, f not defined constexpr int f() { return 5; } // define f, … Read more