https://issues.dlang.org/show_bug.cgi?id=15061
Issue ID: 15061 Summary: std.experimental.logger uses @safe on function templates Product: D Version: D2 Hardware: All OS: All Status: NEW Severity: normal Priority: P1 Component: phobos Assignee: nob...@puremagic.com Reporter: renezwanenb...@gmail.com This means I can't log structs with a custom toString(). For example, import std.experimental.logger; struct S { string toString() { return ""; } } void main() { S s; tracef("%s", s); } Results in Error: safe function 'std.experimental.logger.core.Logger.memLogFunctions!cast(LogLevel)cast(ubyte)32u.logImplf!(15, "test.d", "test.main", "void test.main()", "test", S).logImplf' cannot call system function 'std.format.formattedWrite!(MsgRange, char, S).formattedWrite' A workaround is to change tracef("%s", s); into tracef("%s", s.toString()); --