Here is a more complete answer for 2018.

These days, a lot of tools allow you to not just mark something as deprecated, but also provide a message. This allows you to tell people when something was deprecated, and maybe point them toward a replacement.

There is still a lot of variety in compiler support:

• C++14 supports [[deprecated]]/[[deprecated(message)]].
• __attribute__((deprecated)) is supported by GCC 4.0+ and ARM 4.1+
• __attribute__((deprecated)) and __attribute__((deprecated(message))) is supported for:
  • GCC 4.5+
  • Several compilers which masquerade as GCC 4.5+ (by setting __GNUC__/__GNUC_MINOR__/__GNUC_PATCHLEVEL__)
  • Intel C/C++ Compiler going back to at least 16 (you can't trust __GNUC__/__GNUC_MINOR__, they just set it to whatever version of GCC is installed)
  • ARM 5.6+
• MSVC supports __declspec(deprecated) since 13.10 (Visual Studio 2003)
• MSVC supports __declspec(deprecated) since 14.0 (Visual Studio 2005)

You can also use [[gnu::deprecated]] in recent versions of clang in C++11, based on __has_cpp_attribute(gnu::deprecated).

I have some macros in Hedley to handle all of this automatically which I keep up to date, but the current version (v2) looks like this:

#if defined(__cplusplus) && (__cplusplus >= 201402L) # define HEDLEY_DEPRECATED(since) [[deprecated("Since " #since)]] # define HEDLEY_DEPRECATED_FOR(since, replacement) [[deprecated("Since " #since "; use " #replacement)]] #elif \ HEDLEY_GCC_HAS_EXTENSION(attribute_deprecated_with_message,4,5,0) || \ HEDLEY_INTEL_VERSION_CHECK(16,0,0) || \ HEDLEY_ARM_VERSION_CHECK(5,6,0) # define HEDLEY_DEPRECATED(since) __attribute__((__deprecated__("Since " #since))) # define HEDLEY_DEPRECATED_FOR(since, replacement) __attribute__((__deprecated__("Since " #since "; use " #replacement))) #elif \ HEDLEY_GCC_HAS_ATTRIBUTE(deprcated,4,0,0) || \ HEDLEY_ARM_VERSION_CHECK(4,1,0) # define HEDLEY_DEPRECATED(since) __attribute__((__deprecated__)) # define HEDLEY_DEPRECATED_FOR(since, replacement) __attribute__((__deprecated__)) #elif HEDLEY_MSVC_VERSION_CHECK(14,0,0) # define HEDLEY_DEPRECATED(since) __declspec(deprecated("Since " # since)) # define HEDLEY_DEPRECATED_FOR(since, replacement) __declspec(deprecated("Since " #since "; use " #replacement)) #elif HEDLEY_MSVC_VERSION_CHECK(13,10,0) # define HEDLEY_DEPRECATED(since) _declspec(deprecated) # define HEDLEY_DEPRECATED_FOR(since, replacement) __declspec(deprecated) #else # define HEDLEY_DEPRECATED(since) # define HEDLEY_DEPRECATED_FOR(since, replacement) #endif 

I'll leave it as an exercise to figure out how to get rid of the *_VERSION_CHECK and *_HAS_ATTRIBUTE macros if you don't want to use Hedley (I wrote Hedley largely so I wouldn't have to think about that on a regular basis).

If you use GLib, you can use the G_DEPRECATED and G_DEPRECATED_FOR macros. They're not as robust as the ones from Hedley, but if you already use GLib there is nothing to add.