Merge pull request #8360 from WebFreak001/is-some-finite-char-input-range

add isSomeFiniteCharInputRange as simplification

Signed-off-by: Nicholas Wilson <thewilsonator@users.noreply.github.com>
Merged-on-behalf-of: Nicholas Wilson <thewilsonator@users.noreply.github.com>

std/conv.d

@@ -50,7 +50,7 @@ module std.conv;
 public import std.ascii : LetterCase;
 
 import std.meta;
-import std.range.primitives;
+import std.range;
 import std.traits;
 import std.typecons : Flag, Yes, No, tuple, isTuple;
 
@@ -1996,7 +1996,7 @@ if (isInputRange!S && isSomeChar!(ElementEncodingType!S) &&
 
 /// ditto
 private T toImpl(T, S)(S value, uint radix)
-if (isInputRange!S && !isInfinite!S && isSomeChar!(ElementEncodingType!S) &&
+if (isSomeFiniteCharInputRange!S &&
     isIntegral!T && is(typeof(parse!T(value, radix))))
 {
     scope(success)

std/file.d

@@ -89,7 +89,7 @@ import std.datetime.date : DateTime;
 import std.datetime.systime : Clock, SysTime, unixTimeToStdTime;
 import std.internal.cstring;
 import std.meta;
-import std.range.primitives;
+import std.range;
 import std.traits;
 import std.typecons;
 
@@ -313,8 +313,7 @@ Throws: $(LREF FileException) on error.
  */
 
 void[] read(R)(R name, size_t upTo = size_t.max)
-if (isInputRange!R && isSomeChar!(ElementEncodingType!R) && !isInfinite!R &&
+if (isSomeFiniteCharInputRange!R && !isConvertibleToString!R)
-    !isConvertibleToString!R)
 {
     static if (isNarrowString!R && is(immutable ElementEncodingType!R == immutable char))
         return readImpl(name, name.tempCString!FSChar(), upTo);
@@ -500,7 +499,7 @@ version (linux) @safe unittest
             $(REF UTFException, std, utf) on UTF decoding error.
 +/
 S readText(S = string, R)(auto ref R name)
-if (isSomeString!S && (isInputRange!R && !isInfinite!R && isSomeChar!(ElementType!R) || is(StringTypeOf!R)))
+if (isSomeString!S && (isSomeFiniteCharInputRange!R || is(StringTypeOf!R)))
 {
     import std.algorithm.searching : startsWith;
     import std.encoding : getBOM, BOM;
@@ -736,8 +735,7 @@ Throws: $(LREF FileException) on error.
 See_also: $(REF toFile, std,stdio)
  */
 void write(R)(R name, const void[] buffer)
-if ((isInputRange!R && !isInfinite!R && isSomeChar!(ElementEncodingType!R) || isSomeString!R) &&
+if ((isSomeFiniteCharInputRange!R || isSomeString!R) && !isConvertibleToString!R)
-    !isConvertibleToString!R)
 {
     static if (isNarrowString!R && is(immutable ElementEncodingType!R == immutable char))
         writeImpl(name, name.tempCString!FSChar(), buffer, false);
@@ -785,8 +783,7 @@ Params:
 Throws: $(LREF FileException) on error.
  */
 void append(R)(R name, const void[] buffer)
-if ((isInputRange!R && !isInfinite!R && isSomeChar!(ElementEncodingType!R) || isSomeString!R) &&
+if ((isSomeFiniteCharInputRange!R || isSomeString!R) && !isConvertibleToString!R)
-    !isConvertibleToString!R)
 {
     static if (isNarrowString!R && is(immutable ElementEncodingType!R == immutable char))
         writeImpl(name, name.tempCString!FSChar(), buffer, true);
@@ -915,10 +912,8 @@ version (Windows) private void writeImpl(scope const(char)[] name, scope const(F
  * Throws: $(LREF FileException) on error.
  */
 void rename(RF, RT)(RF from, RT to)
-if ((isInputRange!RF && !isInfinite!RF && isSomeChar!(ElementEncodingType!RF) || isSomeString!RF)
+if ((isSomeFiniteCharInputRange!RF || isSomeString!RF) && !isConvertibleToString!RF &&
-    && !isConvertibleToString!RF &&
+    (isSomeFiniteCharInputRange!RT || isSomeString!RT) && !isConvertibleToString!RT)
-    (isInputRange!RT && !isInfinite!RT && isSomeChar!(ElementEncodingType!RT) || isSomeString!RT)
-    && !isConvertibleToString!RT)
 {
     // Place outside of @trusted block
     auto fromz = from.tempCString!FSChar();
@@ -1027,8 +1022,7 @@ Params:
 Throws: $(LREF FileException) on error.
  */
 void remove(R)(R name)
-if (isInputRange!R && !isInfinite!R && isSomeChar!(ElementEncodingType!R) &&
+if (isSomeFiniteCharInputRange!R && !isConvertibleToString!R)
-    !isConvertibleToString!R)
 {
     static if (isNarrowString!R && is(immutable ElementEncodingType!R == immutable char))
         removeImpl(name, name.tempCString!FSChar());
@@ -1082,7 +1076,7 @@ private void removeImpl(scope const(char)[] name, scope const(FSChar)* namez) @t
 }
 
 version (Windows) private WIN32_FILE_ATTRIBUTE_DATA getFileAttributesWin(R)(R name)
-if (isInputRange!R && !isInfinite!R && isSomeChar!(ElementEncodingType!R))
+if (isSomeFiniteCharInputRange!R)
 {
     auto namez = name.tempCString!FSChar();
 
@@ -1137,8 +1131,7 @@ Throws:
     $(LREF FileException) on error (e.g., file not found).
  */
 ulong getSize(R)(R name)
-if (isInputRange!R && !isInfinite!R && isSomeChar!(ElementEncodingType!R) &&
+if (isSomeFiniteCharInputRange!R && !isConvertibleToString!R)
-    !isConvertibleToString!R)
 {
     version (Windows)
     {
@@ -1233,8 +1226,7 @@ private SysTime statTimeToStdTime(char which)(ref const stat_t statbuf)
 void getTimes(R)(R name,
               out SysTime accessTime,
               out SysTime modificationTime)
-if (isInputRange!R && !isInfinite!R && isSomeChar!(ElementEncodingType!R) &&
+if (isSomeFiniteCharInputRange!R && !isConvertibleToString!R)
-    !isConvertibleToString!R)
 {
     version (Windows)
     {
@@ -1378,8 +1370,9 @@ version (StdDdoc)
                         out SysTime fileCreationTime,
                         out SysTime fileAccessTime,
                         out SysTime fileModificationTime)
-    if (isInputRange!R && !isInfinite!R && isSomeChar!(ElementEncodingType!R) &&
+    if (isSomeFiniteCharInputRange!R || isConvertibleToString!R);
-        !isConvertibleToString!R);
+    // above line contains both constraints for docs
+    // (so users know how it can be called)
 }
 else version (Windows)
 {
@@ -1387,8 +1380,7 @@ else version (Windows)
                         out SysTime fileCreationTime,
                         out SysTime fileAccessTime,
                         out SysTime fileModificationTime)
-    if (isInputRange!R && !isInfinite!R && isSomeChar!(ElementEncodingType!R) &&
+    if (isSomeFiniteCharInputRange!R && !isConvertibleToString!R)
-        !isConvertibleToString!R)
     {
         import std.datetime.systime : FILETIMEToSysTime;
 
@@ -1509,8 +1501,7 @@ private
 void setTimes(R)(R name,
               SysTime accessTime,
               SysTime modificationTime)
-if (isInputRange!R && !isInfinite!R && isSomeChar!(ElementEncodingType!R) &&
+if (isSomeFiniteCharInputRange!R && !isConvertibleToString!R)
-    !isConvertibleToString!R)
 {
     auto namez = name.tempCString!FSChar();
     static if (isNarrowString!R && is(immutable ElementEncodingType!R == immutable char))
@@ -1657,8 +1648,7 @@ private void setTimesImpl(scope const(char)[] names, scope const(FSChar)* namez,
         $(LREF FileException) if the given file does not exist.
 +/
 SysTime timeLastModified(R)(R name)
-if (isInputRange!R && !isInfinite!R && isSomeChar!(ElementEncodingType!R) &&
+if (isSomeFiniteCharInputRange!R && !isConvertibleToString!R)
-    !isConvertibleToString!R)
 {
     version (Windows)
     {
@@ -1742,7 +1732,7 @@ else
 --------------------
 +/
 SysTime timeLastModified(R)(R name, SysTime returnIfMissing)
-if (isInputRange!R && !isInfinite!R && isSomeChar!(ElementEncodingType!R))
+if (isSomeFiniteCharInputRange!R)
 {
     version (Windows)
     {
@@ -1902,8 +1892,7 @@ version (OSX) {} else
  *    true if the file _name specified as input _exists
  */
 bool exists(R)(R name)
-if (isInputRange!R && !isInfinite!R && isSomeChar!(ElementEncodingType!R) &&
+if (isSomeFiniteCharInputRange!R && !isConvertibleToString!R)
-    !isConvertibleToString!R)
 {
     return existsImpl(name.tempCString!FSChar());
 }
@@ -2004,8 +1993,7 @@ private bool existsImpl(scope const(FSChar)* namez) @trusted nothrow @nogc
  Throws: $(LREF FileException) on error.
   +/
 uint getAttributes(R)(R name)
-if (isInputRange!R && !isInfinite!R && isSomeChar!(ElementEncodingType!R) &&
+if (isSomeFiniteCharInputRange!R && !isConvertibleToString!R)
-    !isConvertibleToString!R)
 {
     version (Windows)
     {
@@ -2105,8 +2093,7 @@ if (isConvertibleToString!R)
         $(LREF FileException) on error.
  +/
 uint getLinkAttributes(R)(R name)
-if (isInputRange!R && !isInfinite!R && isSomeChar!(ElementEncodingType!R) &&
+if (isSomeFiniteCharInputRange!R && !isConvertibleToString!R)
-    !isConvertibleToString!R)
 {
     version (Windows)
     {
@@ -2214,8 +2201,7 @@ if (isConvertibleToString!R)
         $(LREF FileException) if the given file does not exist.
  +/
 void setAttributes(R)(R name, uint attributes)
-if (isInputRange!R && !isInfinite!R && isSomeChar!(ElementEncodingType!R) &&
+if (isSomeFiniteCharInputRange!R && !isConvertibleToString!R)
-    !isConvertibleToString!R)
 {
     version (Windows)
     {
@@ -2323,8 +2309,7 @@ if (isConvertibleToString!R)
         $(LREF FileException) if the given file does not exist.
   +/
 @property bool isDir(R)(R name)
-if (isInputRange!R && !isInfinite!R && isSomeChar!(ElementEncodingType!R) &&
+if (isSomeFiniteCharInputRange!R && !isConvertibleToString!R)
-    !isConvertibleToString!R)
 {
     version (Windows)
     {
@@ -2503,8 +2488,7 @@ bool attrIsDir(uint attributes) @safe pure nothrow @nogc
         $(LREF FileException) if the given file does not exist.
 +/
 @property bool isFile(R)(R name)
-if (isInputRange!R && !isInfinite!R && isSomeChar!(ElementEncodingType!R) &&
+if (isSomeFiniteCharInputRange!R && !isConvertibleToString!R)
-    !isConvertibleToString!R)
 {
     version (Windows)
         return !name.isDir;
@@ -2679,8 +2663,7 @@ bool attrIsFile(uint attributes) @safe pure nothrow @nogc
         $(LREF FileException) if the given file does not exist.
   +/
 @property bool isSymlink(R)(R name)
-if (isInputRange!R && !isInfinite!R && isSomeChar!(ElementEncodingType!R) &&
+if (isSomeFiniteCharInputRange!R && !isConvertibleToString!R)
-    !isConvertibleToString!R)
 {
     version (Windows)
         return (getAttributes(name) & FILE_ATTRIBUTE_REPARSE_POINT) != 0;
@@ -2860,8 +2843,7 @@ Params:
 Throws: $(LREF FileException) on error.
  */
 void chdir(R)(R pathname)
-if (isInputRange!R && !isInfinite!R && isSomeChar!(ElementEncodingType!R) &&
+if (isSomeFiniteCharInputRange!R && !isConvertibleToString!R)
-    !isConvertibleToString!R)
 {
     // Place outside of @trusted block
     auto pathz = pathname.tempCString!FSChar();
@@ -2931,8 +2913,7 @@ Throws:
     if an error occured.
  */
 void mkdir(R)(R pathname)
-if (isInputRange!R && !isInfinite!R && isSomeChar!(ElementEncodingType!R) &&
+if (isSomeFiniteCharInputRange!R && !isConvertibleToString!R)
-    !isConvertibleToString!R)
 {
     // Place outside of @trusted block
     const pathz = pathname.tempCString!FSChar();
@@ -3135,8 +3116,7 @@ Params:
 Throws: $(LREF FileException) on error.
  */
 void rmdir(R)(R pathname)
-if (isInputRange!R && !isInfinite!R && isSomeChar!(ElementEncodingType!R) &&
+if (isSomeFiniteCharInputRange!R && !isConvertibleToString!R)
-    !isConvertibleToString!R)
 {
     // Place outside of @trusted block
     auto pathz = pathname.tempCString!FSChar();
@@ -3202,15 +3182,11 @@ if (isConvertibleToString!R)
         exists).
   +/
 version (StdDdoc) void symlink(RO, RL)(RO original, RL link)
-if ((isInputRange!RO && !isInfinite!RO && isSomeChar!(ElementEncodingType!RO) ||
+if ((isSomeFiniteCharInputRange!RO || isConvertibleToString!RO) &&
-    isConvertibleToString!RO) &&
+    (isSomeFiniteCharInputRange!RL || isConvertibleToString!RL));
-    (isInputRange!RL && !isInfinite!RL && isSomeChar!(ElementEncodingType!RL) ||
-    isConvertibleToString!RL));
 else version (Posix) void symlink(RO, RL)(RO original, RL link)
-if ((isInputRange!RO && !isInfinite!RO && isSomeChar!(ElementEncodingType!RO) ||
+if ((isSomeFiniteCharInputRange!RO || isConvertibleToString!RO) &&
-    isConvertibleToString!RO) &&
+    (isSomeFiniteCharInputRange!RL || isConvertibleToString!RL))
-    (isInputRange!RL && !isInfinite!RL && isSomeChar!(ElementEncodingType!RL) ||
-    isConvertibleToString!RL))
 {
     static if (isConvertibleToString!RO || isConvertibleToString!RL)
     {
@@ -3291,11 +3267,9 @@ version (Posix) @safe unittest
         $(LREF FileException) on error.
   +/
 version (StdDdoc) string readLink(R)(R link)
-if (isInputRange!R && !isInfinite!R && isSomeChar!(ElementEncodingType!R) ||
+if (isSomeFiniteCharInputRange!R || isConvertibleToString!R);
-    isConvertibleToString!R);
 else version (Posix) string readLink(R)(R link)
-if (isInputRange!R && !isInfinite!R && isSomeChar!(ElementEncodingType!R) ||
+if (isSomeFiniteCharInputRange!R || isConvertibleToString!R)
-    isConvertibleToString!R)
 {
     static if (isConvertibleToString!R)
     {
@@ -4216,8 +4190,8 @@ Params:
 Throws: $(LREF FileException) on error.
  */
 void copy(RF, RT)(RF from, RT to, PreserveAttributes preserve = preserveAttributesDefault)
-if (isInputRange!RF && !isInfinite!RF && isSomeChar!(ElementEncodingType!RF) && !isConvertibleToString!RF &&
+if (isSomeFiniteCharInputRange!RF && !isConvertibleToString!RF &&
-    isInputRange!RT && !isInfinite!RT && isSomeChar!(ElementEncodingType!RT) && !isConvertibleToString!RT)
+    isSomeFiniteCharInputRange!RT && !isConvertibleToString!RT)
 {
     // Place outside of @trusted block
     auto fromz = from.tempCString!FSChar();
@@ -4781,7 +4755,7 @@ private struct DirIteratorImpl
     }
 
     this(R)(R pathname, SpanMode mode, bool followSymlink)
-        if (isInputRange!R && isSomeChar!(ElementEncodingType!R))
+        if (isSomeFiniteCharInputRange!R)
     {
         _mode = mode;
         _followSymlink = followSymlink;

std/json.d

@@ -19,7 +19,7 @@ module std.json;
 
 import std.array;
 import std.conv;
-import std.range.primitives;
+import std.range;
 import std.traits;
 
 ///
@@ -929,7 +929,7 @@ Params:
     options = enable decoding string representations of NaN/Inf as float values
 */
 JSONValue parseJSON(T)(T json, int maxDepth = -1, JSONOptions options = JSONOptions.none)
-if (isInputRange!T && !isInfinite!T && isSomeChar!(ElementEncodingType!T))
+if (isSomeFiniteCharInputRange!T)
 {
     import std.ascii : isDigit, isHexDigit, toUpper, toLower;
     import std.typecons : Nullable, Yes;
@@ -1437,7 +1437,7 @@ Params:
     options = enable decoding string representations of NaN/Inf as float values
 */
 JSONValue parseJSON(T)(T json, JSONOptions options)
-if (isInputRange!T && !isInfinite!T && isSomeChar!(ElementEncodingType!T))
+if (isSomeFiniteCharInputRange!T)
 {
     return parseJSON!T(json, -1, options);
 }

std/path.d

@@ -98,7 +98,7 @@ module std.path;
 
 import std.file : getcwd;
 static import std.meta;
-import std.range.primitives;
+import std.range;
 import std.traits;
 
 version (OSX)
@@ -262,8 +262,7 @@ version (Windows)
     from a path.
 */
 private auto ltrimDirSeparators(R)(R path)
-if (isInputRange!R && !isInfinite!R && isSomeChar!(ElementType!R) ||
+if (isSomeFiniteCharInputRange!R || isNarrowString!R)
-    isNarrowString!R)
 {
     static if (isRandomAccessRange!R && hasSlicing!R || isNarrowString!R)
     {
@@ -3213,12 +3212,8 @@ int filenameCharCmp(CaseSensitive cs = CaseSensitive.osDefault)(dchar a, dchar b
 */
 int filenameCmp(CaseSensitive cs = CaseSensitive.osDefault, Range1, Range2)
     (Range1 filename1, Range2 filename2)
-if (isInputRange!Range1 && !isInfinite!Range1 &&
+if (isSomeFiniteCharInputRange!Range1 && !isConvertibleToString!Range1 &&
-    isSomeChar!(ElementEncodingType!Range1) &&
+    isSomeFiniteCharInputRange!Range2 && !isConvertibleToString!Range2)
-    !isConvertibleToString!Range1 &&
-    isInputRange!Range2 && !isInfinite!Range2 &&
-    isSomeChar!(ElementEncodingType!Range2) &&
-    !isConvertibleToString!Range2)
 {
     alias C1 = Unqual!(ElementEncodingType!Range1);
     alias C2 = Unqual!(ElementEncodingType!Range2);

std/process.d

@@ -106,9 +106,8 @@ version (Windows)
 }
 
 import std.internal.cstring;
-import std.range.primitives;
+import std.range;
 import std.stdio;
-import std.traits : isSomeChar;
 
 version (OSX)
     version = Darwin;
@@ -1527,7 +1526,7 @@ package(std) string searchPathFor(scope const(char)[] executable)
 // current user.
 version (Posix)
 private bool isExecutable(R)(R path) @trusted nothrow @nogc
-if (isInputRange!R && isSomeChar!(ElementEncodingType!R))
+if (isSomeFiniteCharInputRange!R)
 {
     return (access(path.tempCString(), X_OK) == 0);
 }

std/range/package.d

@@ -13521,3 +13521,49 @@ pure @safe unittest
 
     assert([1, 2, 3, 4].padRight(0, 10)[7 .. 9].equal([0, 0]));
 }
+
+/**
+This simplifies a commonly used idiom in phobos for accepting any kind of string
+parameter. The type `R` can for example be a simple string, chained string using
+$(REF chain, std,range), $(REF chainPath, std,path) or any other input range of
+characters.
+
+Only finite length character ranges are allowed with this constraint.
+
+This template is equivalent to:
+---
+isInputRange!R && !isInfinite!R && isSomeChar!(ElementEncodingType!R)
+---
+
+See_Also:
+$(REF isInputRange, std,range,primitives),
+$(REF isInfinite, std,range,primitives),
+$(LREF isSomeChar),
+$(REF ElementEncodingType, std,range,primitives)
+*/
+template isSomeFiniteCharInputRange(R)
+{
+    import std.traits : isSomeChar;
+
+    enum isSomeFiniteCharInputRange = isInputRange!R && !isInfinite!R
+        && isSomeChar!(ElementEncodingType!R);
+}
+
+///
+@safe unittest
+{
+    import std.path : chainPath;
+    import std.range : chain;
+
+    void someLibraryMethod(R)(R argument)
+    if (isSomeFiniteCharInputRange!R)
+    {
+        // implementation detail, would iterate over each character of argument
+    }
+
+    someLibraryMethod("simple strings work");
+    someLibraryMethod(chain("chained", " ", "strings", " ", "work"));
+    someLibraryMethod(chainPath("chained", "paths", "work"));
+    // you can also use custom structs implementing a char range
+}
+

std/stdio.d

@@ -50,8 +50,8 @@ import core.stdc.stddef : wchar_t;
 public import core.stdc.stdio;
 import std.algorithm.mutation : copy;
 import std.meta : allSatisfy;
-import std.range.primitives : ElementEncodingType, empty, front,
+import std.range : ElementEncodingType, empty, front, isBidirectionalRange,
-    isBidirectionalRange, isInputRange, put;
+    isInputRange, isSomeFiniteCharInputRange, put;
 import std.traits : isSomeChar, isSomeString, Unqual, isPointer;
 import std.typecons : Flag, No, Yes;
 
@@ -555,7 +555,7 @@ Throws: `ErrnoException` if the file could not be opened.
 
     /// ditto
     this(R1, R2)(R1 name)
-        if (isInputRange!R1 && isSomeChar!(ElementEncodingType!R1))
+        if (isSomeFiniteCharInputRange!R1)
     {
         import std.conv : to;
         this(name.to!string, "rb");
@@ -563,8 +563,8 @@ Throws: `ErrnoException` if the file could not be opened.
 
     /// ditto
     this(R1, R2)(R1 name, R2 mode)
-        if (isInputRange!R1 && isSomeChar!(ElementEncodingType!R1) &&
+        if (isSomeFiniteCharInputRange!R1 &&
-            isInputRange!R2 && isSomeChar!(ElementEncodingType!R2))
+            isSomeFiniteCharInputRange!R2)
     {
         import std.conv : to;
         this(name.to!string, mode.to!string);
@@ -4642,8 +4642,8 @@ if (isSomeChar!C && is(Unqual!C == C) && !is(C == enum) &&
  * with appropriately-constructed C-style strings.
  */
 private FILE* _fopen(R1, R2)(R1 name, R2 mode = "r")
-if ((isInputRange!R1 && isSomeChar!(ElementEncodingType!R1) || isSomeString!R1) &&
+if ((isSomeFiniteCharInputRange!R1 || isSomeString!R1) &&
-    (isInputRange!R2 && isSomeChar!(ElementEncodingType!R2) || isSomeString!R2))
+    (isSomeFiniteCharInputRange!R2 || isSomeString!R2))
 {
     import std.internal.cstring : tempCString;
 
@@ -4684,8 +4684,8 @@ version (Posix)
      * with appropriately-constructed C-style strings.
      */
     FILE* _popen(R1, R2)(R1 name, R2 mode = "r") @trusted nothrow @nogc
-    if ((isInputRange!R1 && isSomeChar!(ElementEncodingType!R1) || isSomeString!R1) &&
+    if ((isSomeFiniteCharInputRange!R1 || isSomeString!R1) &&
-        (isInputRange!R2 && isSomeChar!(ElementEncodingType!R2) || isSomeString!R2))
+        (isSomeFiniteCharInputRange!R2 || isSomeString!R2))
     {
         import std.internal.cstring : tempCString;
 

std/utf.d

@@ -65,9 +65,9 @@ module std.utf;
 import std.exception : basicExceptionCtors;
 import core.exception : UnicodeException;
 import std.meta : AliasSeq;
-import std.range.primitives;
+import std.range;
-import std.traits : isAutodecodableString, isPointer, isSomeChar,
+import std.traits : isAutodecodableString, isConvertibleToString, isPointer,
-    isSomeString, isStaticArray, Unqual, isConvertibleToString;
+    isSomeChar, isSomeString, isStaticArray, Unqual;
 import std.typecons : Flag, Yes, No;
 
 
@@ -2809,7 +2809,7 @@ if (isSomeChar!C)
         The number of code units in `input` when encoded to `C`
   +/
 size_t codeLength(C, InputRange)(InputRange input)
-if (isInputRange!InputRange && !isInfinite!InputRange && isSomeChar!(ElementType!InputRange))
+if (isSomeFiniteCharInputRange!InputRange)
 {
     alias EncType = Unqual!(ElementEncodingType!InputRange);
     static if (isSomeString!InputRange && is(EncType == C) && is(typeof(input.length)))
@@ -2961,7 +2961,7 @@ if (isSomeString!S)
  *     For a lazy, non-allocating version of these functions, see $(LREF byUTF).
  */
 string toUTF8(S)(S s)
-if (isInputRange!S && !isInfinite!S && isSomeChar!(ElementEncodingType!S))
+if (isSomeFiniteCharInputRange!S)
 {
     return toUTFImpl!string(s);
 }
@@ -3003,7 +3003,7 @@ if (isInputRange!S && !isInfinite!S && isSomeChar!(ElementEncodingType!S))
  *     For a lazy, non-allocating version of these functions, see $(LREF byUTF).
  */
 wstring toUTF16(S)(S s)
-if (isInputRange!S && !isInfinite!S && isSomeChar!(ElementEncodingType!S))
+if (isSomeFiniteCharInputRange!S)
 {
     return toUTFImpl!wstring(s);
 }
@@ -3047,7 +3047,7 @@ if (isInputRange!S && !isInfinite!S && isSomeChar!(ElementEncodingType!S))
  *     For a lazy, non-allocating version of these functions, see $(LREF byUTF).
  */
 dstring toUTF32(S)(scope S s)
-if (isInputRange!S && !isInfinite!S && isSomeChar!(ElementEncodingType!S))
+if (isSomeFiniteCharInputRange!S)
 {
     return toUTFImpl!dstring(s);
 }