15 Preprocessing directives [cpp]

15.4 Resource inclusion [cpp.embed]

15.4.2 Embed parameters [cpp.embed.param]

15.4.2.1 limit parameter [cpp.embed.param.limit]

1
#
An embed-parameter of the form limit ( pp-balanced-token-seq ) specifies the maximum possible number of elements in the comma-delimited list.
It shall appear at most once in the embed-parameter-seq.
The preprocessing token defined shall not appear in the pp-balanced-token-seq.
2
#
The pp-balanced-token-seq is evaluated as a constant-expression using the rules as described in conditional inclusion ([cpp.cond]), but without being processed as in normal text an additional time.
[Example 1: #undef DATA_LIMIT #if __has_embed(<data.dat> limit(DATA_LIMIT)) #endif
is equivalent to:
#if __has_embed(<data.dat> limit(0)) #endif — end example]
[Example 2: #embed <data.dat> limit(__has_include("a.h")) #if __has_embed(<data.dat> limit(__has_include("a.h"))) // ill-formed: __has_include ([cpp.cond]) cannot appear here #endif — end example]
3
#
The constant-expression shall be an integral constant expression whose value is greater than or equal to zero.
[Example 3: constexpr unsigned char sound_signature[] = { // a hypothetical resource capable of expanding to four or more elements #embed <sdk/jump.wav> limit(2+2) }; static_assert(sizeof(sound_signature) == 4); // OK — end example]