Return true if the specified string having the specified length (in bytes) contains valid UTF-8, and false otherwise. If string contains invalid UTF-8, load into the specified invalidString the address of the byte after the last valid code point traversed; invalidString is unaffected if string contains only valid UTF-8. string need not be null-terminated and can contain embedded null bytes, and string may be null if 0 == length (see {Empty Input Strings}).
Declared in <bdlde_utf8util.h>
static
bool
isValid(
char const** invalidString,
char const* string,
size_type length);