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author | Boris Kolpackov <boris@codesynthesis.com> | 2018-08-09 09:36:23 +0200 |
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committer | Boris Kolpackov <boris@codesynthesis.com> | 2018-08-09 09:36:23 +0200 |
commit | 67b36b32e19e17db9b1e5c72deb8db7202a0f41b (patch) | |
tree | 6c8141f43232569ff930c401b40f74f130743696 /build2/function.hxx | |
parent | 4ce9366b563ceb4939403dbf498b6a5126661ee0 (diff) |
Add support for returning optional<T> from (buildfile) function implementations
Diffstat (limited to 'build2/function.hxx')
-rw-r--r-- | build2/function.hxx | 6 |
1 files changed, 5 insertions, 1 deletions
diff --git a/build2/function.hxx b/build2/function.hxx index 139f1fa..5b84a69 100644 --- a/build2/function.hxx +++ b/build2/function.hxx @@ -46,12 +46,16 @@ namespace build2 // are conceptually "moved" and can be reused by the implementation. // // A function can also optionally receive the current scope by having the - // first argument of the const scope* type. It may be NULL is the function + // first argument of the const scope* type. It may be NULL if the function // is called out of any scope (e.g., command line). // // Note also that we don't pass the location to the function instead // printing the info message pointing to the call site. // + // A function can return value or anything that can be converted to value. + // In particular, if a function returns optional<T>, then the result will be + // either NULL or value of type T. + // // Normally functions come in families that share a common qualification // (e.g., string. or path.). The function_family class is a "registrar" // that simplifies handling of function families. For example: |