PR libstdc++/83025 fix constraints for path overloads in <fstream>

	PR libstdc++/83025
	* include/std/fstream (basic_filebuf::_If_path): Move to
	namespace-scope and rename to _If_fs_path.
	(basic_filebuf::open): Use new name.
	(basic_ifstream(_Path, ios::openmode))
	(basic_ifstream::open(_Path, ios::openmode))
	(basic_ofstream(_Path, ios::openmode))
	(basic_ofstream::open(_Path, ios::openmode))
	(basic_fstream(_Path, ios::openmode))
	(basic_fstream::open(_Path, ios::openmode)): Use _If_fs_path.
	* testsuite/27_io/basic_filebuf/open/char/path.cc: Test with filename
	as non-const char*.
	* testsuite/27_io/basic_fstream/cons/char/path.cc: Likewise.
	* testsuite/27_io/basic_fstream/open/char/path.cc: Likewise.
	* testsuite/27_io/basic_ifstream/cons/char/path.cc: Likewise.
	* testsuite/27_io/basic_ifstream/open/char/path.cc: Likewise.
	* testsuite/27_io/basic_ofstream/cons/char/path.cc: Likewise.
	* testsuite/27_io/basic_ofstream/open/char/path.cc: Likewise.

From-SVN: r254871

7 files changed, 54 insertions, 7 deletions

diff --git a/libstdc++-v3/testsuite/27_io/basic_filebuf/open/char/path.cc b/libstdc++-v3/testsuite/27_io/basic_filebuf/open/char/path.cc
index 56fffde5f9b..51f0839394b 100644
--- a/libstdc++-v3/testsuite/27_io/basic_filebuf/open/char/path.cc
+++ b/libstdc++-v3/testsuite/27_io/basic_filebuf/open/char/path.cc
@@ -24,7 +24,8 @@
 #include <filesystem>
 #include <testsuite_hooks.h>
 
-const std::filesystem::path filename = "filebuf_members-1.tst";
+char cstr[] = "filebuf_members-1.tst";
+const std::filesystem::path filename = cstr;
 
 void
 test01()
@@ -34,6 +35,13 @@ test01()
   VERIFY( fb.is_open() );
 }
 
+void
+test02() // compile-only
+{
+  std::filebuf fb;
+  fb.open(cstr, std::ios::in);	// PR libstdc++/83025
+}
+
 int
 main()
 {
diff --git a/libstdc++-v3/testsuite/27_io/basic_fstream/cons/char/path.cc b/libstdc++-v3/testsuite/27_io/basic_fstream/cons/char/path.cc
index 51337ebd909..079ebe2d04e 100644
--- a/libstdc++-v3/testsuite/27_io/basic_fstream/cons/char/path.cc
+++ b/libstdc++-v3/testsuite/27_io/basic_fstream/cons/char/path.cc
@@ -40,10 +40,14 @@ test02()
   VERIFY( f.is_open() );
 }
 
+using std::is_constructible_v;
+// PR libstdc++/83025
+static_assert(is_constructible_v<std::fstream, char*>);
+static_assert(is_constructible_v<std::fstream, char*, std::ios::openmode>);
+
 int
 main()
 {
   test01();
   test02();
-  return 0;
 }
diff --git a/libstdc++-v3/testsuite/27_io/basic_fstream/open/char/path.cc b/libstdc++-v3/testsuite/27_io/basic_fstream/open/char/path.cc
index 8d0127be2b8..297c8973ca1 100644
--- a/libstdc++-v3/testsuite/27_io/basic_fstream/open/char/path.cc
+++ b/libstdc++-v3/testsuite/27_io/basic_fstream/open/char/path.cc
@@ -24,7 +24,8 @@
 #include <filesystem>
 #include <testsuite_hooks.h>
 
-const std::filesystem::path filename = "ofstream_members-1.tst";
+char cstr[] = "filebuf_members-1.tst";
+const std::filesystem::path filename = cstr;
 
 void
 test01()
@@ -42,6 +43,14 @@ test02()
   VERIFY( f.is_open() );
 }
 
+void
+test03() // compile-only
+{
+  std::fstream f;
+  f.open(cstr);				    // PR libstdc++/83025
+  f.open(cstr, std::ios::in|std::ios::out); // PR libstdc++/83025
+}
+
 int
 main()
 {
diff --git a/libstdc++-v3/testsuite/27_io/basic_ifstream/cons/char/path.cc b/libstdc++-v3/testsuite/27_io/basic_ifstream/cons/char/path.cc
index a0de4ba55b2..4265149752b 100644
--- a/libstdc++-v3/testsuite/27_io/basic_ifstream/cons/char/path.cc
+++ b/libstdc++-v3/testsuite/27_io/basic_ifstream/cons/char/path.cc
@@ -40,10 +40,14 @@ test02()
   VERIFY( f.is_open() );
 }
 
+using std::is_constructible_v;
+// PR libstdc++/83025
+static_assert(is_constructible_v<std::fstream, char*>);
+static_assert(is_constructible_v<std::fstream, char*, std::ios::openmode>);
+
 int
 main()
 {
   test01();
   test02();
-  return 0;
 }
diff --git a/libstdc++-v3/testsuite/27_io/basic_ifstream/open/char/path.cc b/libstdc++-v3/testsuite/27_io/basic_ifstream/open/char/path.cc
index 192e0fe9e85..49b8c1e4dc4 100644
--- a/libstdc++-v3/testsuite/27_io/basic_ifstream/open/char/path.cc
+++ b/libstdc++-v3/testsuite/27_io/basic_ifstream/open/char/path.cc
@@ -24,7 +24,8 @@
 #include <filesystem>
 #include <testsuite_hooks.h>
 
-const std::filesystem::path filename = "ifstream_members-1.tst";
+char cstr[] = "filebuf_members-1.tst";
+const std::filesystem::path filename = cstr;
 
 void
 test01()
@@ -42,6 +43,14 @@ test02()
   VERIFY( f.is_open() );
 }
 
+void
+test03() // compile-only
+{
+  std::ifstream f;
+  f.open(cstr);		      // PR libstdc++/83025
+  f.open(cstr, std::ios::in); // PR libstdc++/83025
+}
+
 int
 main()
 {
diff --git a/libstdc++-v3/testsuite/27_io/basic_ofstream/cons/char/path.cc b/libstdc++-v3/testsuite/27_io/basic_ofstream/cons/char/path.cc
index c6b6b237dfd..da88ff979c4 100644
--- a/libstdc++-v3/testsuite/27_io/basic_ofstream/cons/char/path.cc
+++ b/libstdc++-v3/testsuite/27_io/basic_ofstream/cons/char/path.cc
@@ -40,6 +40,11 @@ test02()
   VERIFY( f.is_open() );
 }
 
+using std::is_constructible_v;
+// PR libstdc++/83025
+static_assert(is_constructible_v<std::fstream, char*>);
+static_assert(is_constructible_v<std::fstream, char*, std::ios::openmode>);
+
 int
 main()
 {
diff --git a/libstdc++-v3/testsuite/27_io/basic_ofstream/open/char/path.cc b/libstdc++-v3/testsuite/27_io/basic_ofstream/open/char/path.cc
index 38078c97ef7..4bbace2c679 100644
--- a/libstdc++-v3/testsuite/27_io/basic_ofstream/open/char/path.cc
+++ b/libstdc++-v3/testsuite/27_io/basic_ofstream/open/char/path.cc
@@ -24,7 +24,8 @@
 #include <filesystem>
 #include <testsuite_hooks.h>
 
-const std::filesystem::path filename = "ofstream_members-1.tst";
+char cstr[] = "filebuf_members-1.tst";
+const std::filesystem::path filename = cstr;
 
 void
 test01()
@@ -42,10 +43,17 @@ test02()
   VERIFY( f.is_open() );
 }
 
+void
+test03() // compile-only
+{
+  std::ofstream f;
+  f.open(cstr);			// PR libstdc++/83025
+  f.open(cstr, std::ios::out);	// PR libstdc++/83025
+}
+
 int
 main()
 {
   test01();
   test02();
-  return 0;
 }