LWG4430 from_chars should not parse "0b" base prefixes

Author: burblebee

source/text.tex

@@ -289,7 +289,10 @@
 in the \tcode{"C"} locale
 for the given nonzero base,
 as described for \tcode{strtol},
-except that no \tcode{"0x"} or \tcode{"0X"} prefix shall appear
+except that
+no \tcode{"0b"} or \tcode{"0B"} prefix shall appear
+if the value of \tcode{base} is 2,
+no \tcode{"0x"} or \tcode{"0X"} prefix shall appear
 if the value of \tcode{base} is 16,
 and except that \tcode{'-'}
 is the only sign that may appear,