stricter to_format check

2015-07-23 00:48:32 +01:00 · 2015-07-23 00:48:32 +01:00 · 0e0ba19ead
parent ad2d69e83d
commit 0e0ba19ead
1 changed files with 2 additions and 3 deletions
--- a/ostd/format.hh
+++ b/ostd/format.hh
@ -399,9 +399,8 @@ protected:
 /* for custom container formatting */

 template<typename T, typename R, typename = EnableIf<
-    IsSame<decltype(declval<T>().to_format(declval<R &>(),
-                                           declval<const FormatSpec &>())),
-           bool
+    IsSame<decltype(declval<const T &>()
+        .to_format(declval<R &>(), declval<const FormatSpec &>())), bool
    >::value
 >> inline bool to_format(const T &v, R &writer, const FormatSpec &fs) {
    return v.to_format(writer, fs);