digitalmars.D.bugs - [Issue 4177] New: __ctfe can't be used in pure functions
- d-bugmail puremagic.com (37/37) May 12 2010 http://d.puremagic.com/issues/show_bug.cgi?id=4177
- d-bugmail puremagic.com (24/24) Jun 08 2010 http://d.puremagic.com/issues/show_bug.cgi?id=4177
- d-bugmail puremagic.com (12/12) Aug 28 2010 http://d.puremagic.com/issues/show_bug.cgi?id=4177
http://d.puremagic.com/issues/show_bug.cgi?id=4177 Summary: __ctfe can't be used in pure functions Product: D Version: future Platform: x86 OS/Version: Windows Status: NEW Keywords: rejects-valid Severity: normal Priority: P2 Component: DMD AssignedTo: nobody puremagic.com ReportedBy: bearophile_hugs eml.cc To define a std.math.log() function that works at compile time (see bug 3749 ) it can be used __ctfe, but there are problems: pure real log(real x) { if (__ctfe) return 0.0; else return 1.0; } enum x = log(4.0); void main() {} dmd v2.045 prints: test.d(2): Error: variable __ctfe forward referenced test.d(2): Error: pure nested function 'log' cannot access mutable data '__ctfe' test.d(7): Error: cannot evaluate log(4L) at compile time test.d(7): Error: cannot evaluate log(4L) at compile time I'd like __ctfe to work in pure functions too. I think it can be done because it's an immutable value that I think can't break the purity of the function/method, even if as in that example the function can give different outouts at compile and run time. -- Configure issuemail: http://d.puremagic.com/issues/userprefs.cgi?tab=email ------- You are receiving this mail because: -------
May 12 2010
http://d.puremagic.com/issues/show_bug.cgi?id=4177 Don <clugdbug yahoo.com.au> changed: What |Removed |Added ---------------------------------------------------------------------------- Keywords| |patch CC| |clugdbug yahoo.com.au Version|future |2.041 Since __ctfe is so magical and unique, it seems justified to give it one more special case. Other approaches I tried (changing the storage_class of __ctfe) were far more complicated. PATCH expression.c, VarExp::semantic(), line 4397. + /* Magic variable __ctfe never violates pure or safe + */ + if (v->ident == Id::ctfe) + return this; /* If ANY of its enclosing functions are pure, * it cannot do anything impure. * If it is pure, it cannot access any mutable variables other * than those inside itself */ -- Configure issuemail: http://d.puremagic.com/issues/userprefs.cgi?tab=email ------- You are receiving this mail because: -------
Jun 08 2010
http://d.puremagic.com/issues/show_bug.cgi?id=4177 Walter Bright <bugzilla digitalmars.com> changed: What |Removed |Added ---------------------------------------------------------------------------- Status|NEW |RESOLVED CC| |bugzilla digitalmars.com Resolution| |FIXED 14:55:16 PDT --- http://www.dsource.org/projects/dmd/changeset/646 -- Configure issuemail: http://d.puremagic.com/issues/userprefs.cgi?tab=email ------- You are receiving this mail because: -------
Aug 28 2010