Drop backwards compatibility workarounds

Author: oprypin

docopt.nimble

@@ -6,4 +6,4 @@ description: "Command line option parser that will make you smile"
 license: "MIT"
 srcDir: "src"
 [Deps]
-requires: "nim >= 0.14.0"
+requires: "nim >= 0.15.0"

src/private/util.nim

@@ -43,13 +43,8 @@ proc partition*(s, sep: string): tuple[left, sep, right: string] =
 
 proc is_upper*(s: string): bool =
     ## Is the string in uppercase (and there is at least one cased character)?
-    # Backwards compatibility
-    when compiles(unicode.to_upper("")):
-        let upper = unicode.to_upper(s)
-        s == upper and upper != unicode.to_lower(s)
-    else:
-        let upper = strutils.to_upper(s)
-        s == upper and upper != strutils.to_lower(s)
+    let upper = unicode.to_upper(s)
+    s == upper and upper != unicode.to_lower(s)
 
 
 macro gen_class*(body: untyped): untyped =
@@ -62,9 +57,3 @@ macro gen_class*(body: untyped): untyped =
         meth &= "= \"$1\""
         body.add(parse_stmt(meth.format(typ[0])))
     body
-
-
-# Backwards compatibility
-when not compiles("".split_whitespace()):
-    proc split_whitespace*(s: string): seq[string] =
-        s.split()