http://d.puremagic.com/issues/show_bug.cgi?id=9456
Summary: decodeFront erroneously alters its input range with reference type ranges Product: D Version: D2 Platform: All OS/Version: All Status: NEW Severity: normal Priority: P2 Component: Phobos AssignedTo: nob...@puremagic.com ReportedBy: jmdavisp...@gmx.com --- Comment #0 from Jonathan M Davis <jmdavisp...@gmx.com> 2013-02-05 17:05:12 PST --- This code import std.array; import std.conv; import std.utf; class RefRange(C) { @property bool empty() { return _str.empty; } @property C front() { return _str[0]; } void popFront() { _str = _str[1 .. $]; } @property C back() { return _str[$ - 1]; } void popBack() { _str = _str[0 .. $ - 1]; } @property auto save() { return new RefRange(_str); } @property size_t length() { return _str.length; } this(inout(C)[] str) { _str = to!(C[])(str); } C[] _str; } void main() { auto asciiStr = "hello world"; auto asciiRange = new RefRange!char(asciiStr); //auto asii = asciiStr; size_t index = 1; assert(asciiRange.decodeFront(index) == 'h'); assert(asciiRange.length == asciiStr.length); auto uniStr = "プログラミング"; auto uniRange = new RefRange!char(uniStr); //auto uniRange = uniStr; index = 3; assert(uniRange.decodeFront(index) == 'プ'); assert(uniRange.length == uniStr.length); } gives this error when it runs core.exception.AssertError@q(37): Assertion failure ---------------- ./q(_d_assertm+0x26) [0x42c946] ./q() [0x42ac22] ./q(_Dmain+0xfa) [0x42a3da] ./q(extern (C) int rt.dmain2._d_run_main(int, char**, extern (C) int function(char[][])*).void runMain()+0x18) [0x42d0dc] ./q(extern (C) int rt.dmain2._d_run_main(int, char**, extern (C) int function(char[][])*).void tryExec(scope void delegate())+0x2a) [0x42cc1a] ./q(extern (C) int rt.dmain2._d_run_main(int, char**, extern (C) int function(char[][])*).void runAll()+0x3b) [0x42d123] ./q(extern (C) int rt.dmain2._d_run_main(int, char**, extern (C) int function(char[][])*).void tryExec(scope void delegate())+0x2a) [0x42cc1a] ./q(_d_run_main+0x1a8) [0x42cbd4] ./q(main+0x17) [0x42ca27] /usr/lib/libc.so.6(__libc_start_main+0xf5) [0x7f60c980aa15] ---------------- The last assertion fails. If you swap which lines are commented out so that strings are used instead of RefRange, then the code succeeds. The problem is that decodeFront calls popFront when dealing with unicode, and it doesn't save, so depending on what's passed to it, it may or may not pop elements. It's more efficient to save internally in the cases where it needs to rather than ask the caller to do so, so the correct fix is to make it save if it's going to pop anything. -- Configure issuemail: http://d.puremagic.com/issues/userprefs.cgi?tab=email ------- You are receiving this mail because: -------