This is an unofficial snapshot of the ISO/IEC JTC1 SC22 WG21 Core Issues List revision 116a. See http://www.open-std.org/jtc1/sc22/wg21/ for the official list.

2024-12-19

831. Limit on recursively nested template instantiations

[Voted into WP at October, 2009 meeting.]

The limit of 17 recursively-nested template instantiations is too small for modern programming practices such as template metaprogramming. It is unclear, however, whether this is a useful metric; see this paper for an example that honors the limit but results in over 750 billion instantiations.

Notes from the July, 2009 meeting:

The consensus of the CWG was to increase the limit to 1024.

Proposed resolution (September, 2009):

Change Clause Annex B [implimits], the fourth bullet from the end, as follows:

• Recursively nested template instantiations [17 1 024].