Constrain isSomeString

dlang · May 25, 2014 · e2e3a70 · e2e3a70
1 parent 0ae323d
commit e2e3a70
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Showing 3 changed files with 25 additions and 13 deletions.
diff --git a/std/format.d b/std/format.d
@@ -4260,7 +4260,7 @@ unittest
    Reads a string and returns it.
  */
 T unformatValue(T, Range, Char)(ref Range input, ref FormatSpec!Char spec)
-    if (isInputRange!Range && isSomeString!T && !is(T == enum))
+    if (isInputRange!Range && is(StringTypeOf!T) && !isAggregateType!T && !is(T == enum))
 {
     if (spec.spec == '(')
     {
@@ -4336,7 +4336,7 @@ unittest
    Reads an array (except for string types) and returns it.
  */
 T unformatValue(T, Range, Char)(ref Range input, ref FormatSpec!Char spec)
-    if (isInputRange!Range && isArray!T && !isSomeString!T && !is(T == enum))
+    if (isInputRange!Range && isArray!T && !is(StringTypeOf!T) && !isAggregateType!T && !is(T == enum))
 {
     if (spec.spec == '(')
     {

diff --git a/std/range.d b/std/range.d
@@ -1479,7 +1479,7 @@ $(D ElementType).
  */
 template ElementEncodingType(R)
 {
-    static if (isNarrowString!R && is(R : E[], E))
+    static if (is(StringTypeOf!R) && is(R : E[], E))
         alias ElementEncodingType = E;
     else
         alias ElementEncodingType = ElementType!R;

diff --git a/std/traits.d b/std/traits.d
@@ -4857,11 +4857,8 @@ template ArrayTypeOf(T)
         static assert(0, T.stringof~" is not an array type");
 }
 
-unittest
-{
-}
-
 /*
+Always returns the Dynamic Array version.
  */
 template StringTypeOf(T)
 {
@@ -4874,7 +4871,10 @@ template StringTypeOf(T)
     }
     else static if (is(T : const char[]) || is(T : const wchar[]) || is(T : const dchar[]))
     {
-        alias StringTypeOf = ArrayTypeOf!T;
+        static if (is(T : U[], U))
+            alias StringTypeOf = U[];
+        else
+            static assert(0);
     }
     else
         static assert(0, T.stringof~" is not a string type");
@@ -4904,6 +4904,11 @@ unittest
         }
 }
 
+unittest
+{
+    static assert(is(StringTypeOf!(char[4]) == char[]));
+}
+
 /*
  */
 template AssocArrayTypeOf(T)
@@ -5133,12 +5138,18 @@ unittest
 
 /**
 Detect whether $(D T) is one of the built-in string types.
+
+The built-in string types are $(D Char[]), where $(D Char) is any of $(D char),
+$(D wchar) or $(D dchar), with or without qualifiers.
+
+Static arrays of characters (like $(D char[80]) are not considered
+built-in string types.
  */
-enum bool isSomeString(T) = is(StringTypeOf!T) && !isAggregateType!T;
+enum bool isSomeString(T) = is(StringTypeOf!T) && !isAggregateType!T && !isStaticArray!T;
 
 unittest
 {
-    foreach (T; TypeTuple!(char[], dchar[], string, wstring, dstring, char[4]))
+    foreach (T; TypeTuple!(char[], dchar[], string, wstring, dstring))
     {
         static assert( isSomeString!(           T ));
         static assert(!isSomeString!(SubTypeOf!(T)));
@@ -5148,16 +5159,17 @@ unittest
     static assert(!isSomeString!(int[]));
     static assert(!isSomeString!(byte[]));
     static assert(!isSomeString!(typeof(null)));
+    static assert(!isSomeString!(char[4]));
 
     enum ES : string { a = "aaa", b = "bbb" }
     static assert( isSomeString!ES);
 }
 
-enum bool isNarrowString(T) = (is(T : const char[]) || is(T : const wchar[])) && !isAggregateType!T;
+enum bool isNarrowString(T) = (is(T : const char[]) || is(T : const wchar[])) && !isAggregateType!T && !isStaticArray!T;
 
 unittest
 {
-    foreach (T; TypeTuple!(char[], string, wstring, char[4]))
+    foreach (T; TypeTuple!(char[], string, wstring))
     {
         foreach (Q; TypeTuple!(MutableOf, ConstOf, ImmutableOf)/*TypeQualifierList*/)
         {
@@ -5166,7 +5178,7 @@ unittest
         }
     }
 
-    foreach (T; TypeTuple!(int, int[], byte[], dchar[], dstring))
+    foreach (T; TypeTuple!(int, int[], byte[], dchar[], dstring, char[4]))
     {
         foreach (Q; TypeQualifierList)
         {