libstdc++: Add helper function in <format>

Add a new __format::__write_padded_as_spec helper to remove duplicated
code in formatter specializations.

libstdc++-v3/ChangeLog:

	* include/std/format (__format::__write_padded_as_spec): New
	function.
	(__format::__formatter_str, __format::__formatter_int::format)
	(formatter<const void*, charT>): Use it.

diff --git a/libstdc++-v3/include/std/format b/libstdc++-v3/include/std/format
index 9c92837..98421e8 100644 (file)
--- a/libstdc++-v3/include/std/format
+++ b/libstdc++-v3/include/std/format
@@ -597,6 +597,7 @@ namespace __format
       return __dest;
     }
 
+  // Write STR to OUT (and do so efficiently if OUT is a _Sink_iter).
   template<typename _Out, typename _CharT>
     requires output_iterator<_Out, const _CharT&>
     inline _Out
@@ -668,6 +669,30 @@ namespace __format
       return __out;
     }
 
+  // Write STR to OUT, with alignment and padding as determined by SPEC.
+  // pre: __spec._M_align != _Align_default || __align != _Align_default
+  template<typename _CharT, typename _Out>
+    _Out
+    __write_padded_as_spec(basic_string_view<type_identity_t<_CharT>> __str,
+                          size_t __estimated_width,
+                          basic_format_context<_Out, _CharT>& __fc,
+                          const _Spec<_CharT>& __spec,
+                          _Align __align = _Align_left)
+    {
+      size_t __width = __spec._M_get_width(__fc);
+
+      if (__width <= __estimated_width)
+       return __format::__write(__fc.out(), __str);
+
+      const size_t __nfill = __width - __estimated_width;
+
+      if (__spec._M_align)
+       __align = __spec._M_align;
+
+      return __format::__write_padded(__fc.out(), __str, __align, __nfill,
+                                     __spec._M_fill);
+    }
+
   // A lightweight optional<locale>.
   struct _Optional_locale
   {
@@ -799,7 +824,7 @@ namespace __format
       }
 
       template<typename _Out>
-       typename basic_format_context<_Out, _CharT>::iterator
+       _Out
        format(basic_string_view<_CharT> __s,
               basic_format_context<_Out, _CharT>& __fc) const
        {
@@ -824,16 +849,8 @@ namespace __format
                }
            }
 
-         size_t __width = _M_spec._M_get_width(__fc);
-
-         if (__width <= __estimated_width)
-           return __format::__write(__fc.out(), __s);
-
-         const size_t __nfill = __width - __estimated_width;
-         _Align __align = _M_spec._M_align ? _M_spec._M_align : _Align_left;
-
-         return __format::__write_padded(__fc.out(), __s,
-                                         __align, __nfill, _M_spec._M_fill);
+         return __format::__write_padded_as_spec(__s, __estimated_width,
+                                                 __fc, _M_spec);
        }
 
 #if __cpp_lib_format_ranges
@@ -1089,32 +1106,16 @@ namespace __format
              __est_width = __s.size();
            }
 
-         return _M_format_str(__s, __est_width, __fc);
+         return __format::__write_padded_as_spec(__s, __est_width, __fc,
+                                                 _M_spec);
        }
 
       template<typename _Out>
        typename basic_format_context<_Out, _CharT>::iterator
        _M_format_character(_CharT __c,
                      basic_format_context<_Out, _CharT>& __fc) const
-       { return _M_format_str({&__c, 1u}, 1, __fc); }
-
-      template<typename _Out>
-       typename basic_format_context<_Out, _CharT>::iterator
-       _M_format_str(basic_string_view<_CharT> __str, size_t __est_width,
-                     basic_format_context<_Out, _CharT>& __fc) const
        {
-         // TODO: this is identical to last part of __formatter_str::format
-         // so refactor to reuse the same code.
-
-         size_t __width = _M_spec._M_get_width(__fc);
-
-         if (__width <= __est_width)
-           return __format::__write(__fc.out(), __str);
-
-         size_t __nfill = __width - __est_width;
-         _Align __align = _M_spec._M_align ? _M_spec._M_align : _Align_left;
-         return __format::__write_padded(__fc.out(), __str,
-                                         __align, __nfill, _M_spec._M_fill);
+         return __format::__write_padded_as_spec({&__c, 1u}, 1, __fc, _M_spec);
        }
 
       template<typename _Int>
@@ -2135,20 +2136,12 @@ namespace __format
              __str = wstring_view(__p, __n);
            }
 
-         size_t __width = _M_spec._M_get_width(__fc);
-
-         if (__width <= (size_t)__n)
-           return __format::__write(__fc.out(), __str);
-
-         size_t __nfill = __width - __n;
-         __format::_Align __align
-           = _M_spec._M_align ? _M_spec._M_align : __format::_Align_right;
-         return __format::__write_padded(__fc.out(), __str,
-                                         __align, __nfill, _M_spec._M_fill);
+         return __format::__write_padded_as_spec(__str, __n, __fc, _M_spec,
+                                                 __format::_Align_right);
        }
 
     private:
-      __format::_Spec<_CharT> _M_spec{}; // XXX don't need full spec?
+      __format::_Spec<_CharT> _M_spec{};
     };
 
   template<__format::__char _CharT>