diff --git a/stl/inc/any b/stl/inc/any
index ff810e276..76f3746bb 100644
--- a/stl/inc/any
+++ b/stl/inc/any
@@ -10,7 +10,7 @@
 #if _STL_COMPILER_PREPROCESSOR
 
 #if !_HAS_CXX17
-#pragma message(_WARNING_MESSAGE("STL4038", "The contents of <any> are available only with C++17 or later."))
+_EMIT_STL_WARNING(STL4038, "The contents of <any> are available only with C++17 or later.");
 #else // ^^^ !_HAS_CXX17 / _HAS_CXX17 vvv
 #include <initializer_list>
 #include <type_traits>
diff --git a/stl/inc/barrier b/stl/inc/barrier
index 37cf1c411..ee2f8d82f 100644
--- a/stl/inc/barrier
+++ b/stl/inc/barrier
@@ -14,7 +14,7 @@
 #endif // _M_CEE_PURE
 
 #if !_HAS_CXX20
-#pragma message(_WARNING_MESSAGE("STL4038", "The contents of <barrier> are available only with C++20 or later."))
+_EMIT_STL_WARNING(STL4038, "The contents of <barrier> are available only with C++20 or later.");
 #else // ^^^ !_HAS_CXX20 / _HAS_CXX20 vvv
 
 #include <atomic>
diff --git a/stl/inc/bit b/stl/inc/bit
index bacde1abf..391c0cdcd 100644
--- a/stl/inc/bit
+++ b/stl/inc/bit
@@ -9,7 +9,7 @@
 #include <yvals_core.h>
 #if _STL_COMPILER_PREPROCESSOR
 #if !_HAS_CXX20
-#pragma message(_WARNING_MESSAGE("STL4038", "The contents of <bit> are available only with C++20 or later."))
+_EMIT_STL_WARNING(STL4038, "The contents of <bit> are available only with C++20 or later.");
 #else // ^^^ !_HAS_CXX20 / _HAS_CXX20 vvv
 
 #include <intrin0.h>
diff --git a/stl/inc/charconv b/stl/inc/charconv
index ab0d54a62..75021352e 100644
--- a/stl/inc/charconv
+++ b/stl/inc/charconv
@@ -10,7 +10,7 @@
 #if _STL_COMPILER_PREPROCESSOR
 
 #if !_HAS_CXX17
-#pragma message(_WARNING_MESSAGE("STL4038", "The contents of <charconv> are available only with C++17 or later."))
+_EMIT_STL_WARNING(STL4038, "The contents of <charconv> are available only with C++17 or later.");
 #else // ^^^ !_HAS_CXX17 / _HAS_CXX17 vvv
 #include <cstring>
 #include <intrin0.h>
diff --git a/stl/inc/compare b/stl/inc/compare
index e46bfd0bd..96aa6d382 100644
--- a/stl/inc/compare
+++ b/stl/inc/compare
@@ -10,7 +10,7 @@
 #if _STL_COMPILER_PREPROCESSOR
 
 #if !_HAS_CXX20
-#pragma message(_WARNING_MESSAGE("STL4038", "The contents of <compare> are available only with C++20 or later."))
+_EMIT_STL_WARNING(STL4038, "The contents of <compare> are available only with C++20 or later.");
 #else // ^^^ !_HAS_CXX20 / _HAS_CXX20 vvv
 #ifdef __cpp_lib_concepts
 #include <bit>
diff --git a/stl/inc/concepts b/stl/inc/concepts
index cd8ceabff..0604da200 100644
--- a/stl/inc/concepts
+++ b/stl/inc/concepts
@@ -10,8 +10,7 @@
 #if _STL_COMPILER_PREPROCESSOR
 
 #ifndef __cpp_lib_concepts
-#pragma message( \
-    _WARNING_MESSAGE("STL4038", "The contents of <concepts> are available only with C++20 concepts support."))
+_EMIT_STL_WARNING(STL4038, "The contents of <concepts> are available only with C++20 concepts support.");
 #else // ^^^ !defined(__cpp_lib_concepts) / defined(__cpp_lib_concepts) vvv
 #include <type_traits>
 #include <vcruntime_new.h>
diff --git a/stl/inc/coroutine b/stl/inc/coroutine
index 6bd8828cf..d884eba9c 100644
--- a/stl/inc/coroutine
+++ b/stl/inc/coroutine
@@ -10,17 +10,12 @@
 #if _STL_COMPILER_PREPROCESSOR
 
 #ifdef _RESUMABLE_FUNCTIONS_SUPPORTED
-#define _STL4039_COROUTINE                                         \
-    "The contents of <coroutine> are not available with /await. "  \
-    "Remove /await or use /await:strict for standard coroutines. " \
-    "Use <experimental/coroutine> for legacy /await support."
-#pragma message(_WARNING_MESSAGE("STL4039", _STL4039_COROUTINE))
-#undef _STL4039_COROUTINE // TRANSITION, DevCom-1479701
+_EMIT_STL_WARNING(STL4039, "The contents of <coroutine> are not available with /await. "
+                           "Remove /await or use /await:strict for standard coroutines. "
+                           "Use <experimental/coroutine> for legacy /await support.");
 #else // ^^^ /await ^^^ / vvv no /await vvv
 #ifndef __cpp_lib_coroutine
-#define _STL4038_COROUTINE "The contents of <coroutine> are available only with C++20 or later or /await:strict."
-#pragma message(_WARNING_MESSAGE("STL4038", _STL4038_COROUTINE))
-#undef _STL4038_COROUTINE // TRANSITION, DevCom-1479701
+_EMIT_STL_WARNING(STL4038, "The contents of <coroutine> are available only with C++20 or later or /await:strict.");
 #else // ^^^ <coroutine> is not available / <coroutine> is available vvv
 #ifndef _ALLOW_COROUTINE_ABI_MISMATCH
 #pragma detect_mismatch("_COROUTINE_ABI", "2")
diff --git a/stl/inc/execution b/stl/inc/execution
index a934df435..6314feb4c 100644
--- a/stl/inc/execution
+++ b/stl/inc/execution
@@ -10,7 +10,7 @@
 #if _STL_COMPILER_PREPROCESSOR
 
 #if !_HAS_CXX17
-#pragma message(_WARNING_MESSAGE("STL4038", "The contents of <execution> are available only with C++17 or later."))
+_EMIT_STL_WARNING(STL4038, "The contents of <execution> are available only with C++17 or later.");
 #else // ^^^ !_HAS_CXX17 / _HAS_CXX17 vvv
 #include <algorithm>
 #include <atomic>
diff --git a/stl/inc/expected b/stl/inc/expected
index 8ee683217..3342db7bb 100644
--- a/stl/inc/expected
+++ b/stl/inc/expected
@@ -9,7 +9,7 @@
 #include <yvals.h>
 #if _STL_COMPILER_PREPROCESSOR
 #ifndef __cpp_lib_expected
-#pragma message(_WARNING_MESSAGE("STL4038", "The contents of <expected> are available only with C++23 or later."))
+_EMIT_STL_WARNING(STL4038, "The contents of <expected> are available only with C++23 or later.");
 #else // ^^^ !__cpp_lib_expected / __cpp_lib_expected vvv
 #include <exception>
 #include <initializer_list>
diff --git a/stl/inc/filesystem b/stl/inc/filesystem
index 0130975f0..34fbee722 100644
--- a/stl/inc/filesystem
+++ b/stl/inc/filesystem
@@ -10,7 +10,7 @@
 #if _STL_COMPILER_PREPROCESSOR
 
 #if !_HAS_CXX17
-#pragma message(_WARNING_MESSAGE("STL4038", "The contents of <filesystem> are available only with C++17 or later."))
+_EMIT_STL_WARNING(STL4038, "The contents of <filesystem> are available only with C++17 or later.");
 #else // ^^^ !_HAS_CXX17 / _HAS_CXX17 vvv
 #include <algorithm>
 #include <chrono>
diff --git a/stl/inc/format b/stl/inc/format
index 44eea00d6..50ca187f1 100644
--- a/stl/inc/format
+++ b/stl/inc/format
@@ -40,7 +40,7 @@
 #include <yvals_core.h>
 #if _STL_COMPILER_PREPROCESSOR
 #ifndef __cpp_lib_format
-#pragma message(_WARNING_MESSAGE("STL4038", "The contents of <format> are available only with C++20 or later."))
+_EMIT_STL_WARNING(STL4038, "The contents of <format> are available only with C++20 or later.");
 #else // ^^^ !defined(__cpp_lib_format) / defined(__cpp_lib_format) vvv
 
 #include <__msvc_format_ucd_tables.hpp>
diff --git a/stl/inc/latch b/stl/inc/latch
index 20554a869..91d32b791 100644
--- a/stl/inc/latch
+++ b/stl/inc/latch
@@ -14,7 +14,7 @@
 #endif // _M_CEE_PURE
 
 #if !_HAS_CXX20
-#pragma message(_WARNING_MESSAGE("STL4038", "The contents of <latch> are available only with C++20 or later."))
+_EMIT_STL_WARNING(STL4038, "The contents of <latch> are available only with C++20 or later.");
 #else // ^^^ !_HAS_CXX20 / _HAS_CXX20 vvv
 
 #include <atomic>
diff --git a/stl/inc/memory_resource b/stl/inc/memory_resource
index 3b7f6828d..743809c9b 100644
--- a/stl/inc/memory_resource
+++ b/stl/inc/memory_resource
@@ -10,8 +10,7 @@
 #if _STL_COMPILER_PREPROCESSOR
 
 #if !_HAS_CXX17
-#pragma message( \
-    _WARNING_MESSAGE("STL4038", "The contents of <memory_resource> are available only with C++17 or later."))
+_EMIT_STL_WARNING(STL4038, "The contents of <memory_resource> are available only with C++17 or later.");
 #else // ^^^ !_HAS_CXX17 / _HAS_CXX17 vvv
 #include <vector>
 #include <xbit_ops.h>
diff --git a/stl/inc/numbers b/stl/inc/numbers
index c302adc42..884c349a4 100644
--- a/stl/inc/numbers
+++ b/stl/inc/numbers
@@ -9,7 +9,7 @@
 #include <yvals_core.h>
 #if _STL_COMPILER_PREPROCESSOR
 #if !_HAS_CXX20
-#pragma message(_WARNING_MESSAGE("STL4038", "The contents of <numbers> are available only with C++20 or later."))
+_EMIT_STL_WARNING(STL4038, "The contents of <numbers> are available only with C++20 or later.");
 #else // ^^^ !_HAS_CXX20 / _HAS_CXX20 vvv
 #ifdef __cpp_lib_concepts
 #include <concepts>
diff --git a/stl/inc/optional b/stl/inc/optional
index f4a0118c0..f70a6ff63 100644
--- a/stl/inc/optional
+++ b/stl/inc/optional
@@ -9,7 +9,7 @@
 #include <yvals.h>
 #if _STL_COMPILER_PREPROCESSOR
 #if !_HAS_CXX17
-#pragma message(_WARNING_MESSAGE("STL4038", "The contents of <optional> are available only with C++17 or later."))
+_EMIT_STL_WARNING(STL4038, "The contents of <optional> are available only with C++17 or later.");
 #else // ^^^ !_HAS_CXX17 / _HAS_CXX17 vvv
 #if _HAS_CXX20
 #include <compare>
diff --git a/stl/inc/ranges b/stl/inc/ranges
index eda6d3e0b..eb12830cb 100644
--- a/stl/inc/ranges
+++ b/stl/inc/ranges
@@ -9,7 +9,7 @@
 #include <yvals_core.h>
 #if _STL_COMPILER_PREPROCESSOR
 #ifndef __cpp_lib_ranges
-#pragma message(_WARNING_MESSAGE("STL4038", "The contents of <ranges> are available only with C++20 or later."))
+_EMIT_STL_WARNING(STL4038, "The contents of <ranges> are available only with C++20 or later.");
 #else // ^^^ !defined(__cpp_lib_ranges) / defined(__cpp_lib_ranges) vvv
 #include <__msvc_int128.hpp>
 #include <iosfwd>
diff --git a/stl/inc/semaphore b/stl/inc/semaphore
index f27e340bf..78a8dd260 100644
--- a/stl/inc/semaphore
+++ b/stl/inc/semaphore
@@ -14,7 +14,7 @@
 #endif // _M_CEE_PURE
 
 #if !_HAS_CXX20
-#pragma message(_WARNING_MESSAGE("STL4038", "The contents of <semaphore> are available only with C++20 or later."))
+_EMIT_STL_WARNING(STL4038, "The contents of <semaphore> are available only with C++20 or later.");
 #else // ^^^ !_HAS_CXX20 / _HAS_CXX20 vvv
 
 #include <__msvc_chrono.hpp>
diff --git a/stl/inc/source_location b/stl/inc/source_location
index cfafe7023..9bbea2160 100644
--- a/stl/inc/source_location
+++ b/stl/inc/source_location
@@ -9,8 +9,7 @@
 #include <yvals_core.h>
 #if _STL_COMPILER_PREPROCESSOR
 #ifndef __cpp_consteval
-#pragma message( \
-    _WARNING_MESSAGE("STL4038", "The contents of <source_location> are available only with C++20 consteval support."))
+_EMIT_STL_WARNING(STL4038, "The contents of <source_location> are available only with C++20 consteval support.");
 #else // ^^^ !defined(__cpp_consteval) / defined(__cpp_consteval) vvv
 
 #include <cstdint>
diff --git a/stl/inc/span b/stl/inc/span
index 55363d4d3..26b24fe3f 100644
--- a/stl/inc/span
+++ b/stl/inc/span
@@ -10,7 +10,7 @@
 #if _STL_COMPILER_PREPROCESSOR
 
 #if !_HAS_CXX20
-#pragma message(_WARNING_MESSAGE("STL4038", "The contents of <span> are available only with C++20 or later."))
+_EMIT_STL_WARNING(STL4038, "The contents of <span> are available only with C++20 or later.");
 #else // ^^^ !_HAS_CXX20 / _HAS_CXX20 vvv
 #include <compare>
 #include <cstddef>
diff --git a/stl/inc/spanstream b/stl/inc/spanstream
index e5f7cda6a..1f92d8bbc 100644
--- a/stl/inc/spanstream
+++ b/stl/inc/spanstream
@@ -9,7 +9,7 @@
 #include <yvals.h>
 #if _STL_COMPILER_PREPROCESSOR
 #if !_HAS_CXX23
-#pragma message(_WARNING_MESSAGE("STL4038", "The contents of <spanstream> are available only with C++23 or later."))
+_EMIT_STL_WARNING(STL4038, "The contents of <spanstream> are available only with C++23 or later.");
 #else // ^^^ !_HAS_CXX23 / _HAS_CXX23 vvv
 #ifdef __cpp_lib_concepts
 #include <concepts>
diff --git a/stl/inc/stacktrace b/stl/inc/stacktrace
index 452b4f089..43f765af5 100644
--- a/stl/inc/stacktrace
+++ b/stl/inc/stacktrace
@@ -10,7 +10,7 @@
 #if _STL_COMPILER_PREPROCESSOR
 
 #if !_HAS_CXX23
-#pragma message(_WARNING_MESSAGE("STL4038", "The contents of <stacktrace> are available only with C++23 or later."))
+_EMIT_STL_WARNING(STL4038, "The contents of <stacktrace> are available only with C++23 or later.");
 #else // ^^^ !_HAS_CXX23 / _HAS_CXX23 vvv
 
 #include <cstdint>
diff --git a/stl/inc/stdatomic.h b/stl/inc/stdatomic.h
index 29838b8c0..2e821f7f9 100644
--- a/stl/inc/stdatomic.h
+++ b/stl/inc/stdatomic.h
@@ -22,7 +22,7 @@
 #endif // _M_CEE_PURE
 
 #if !_HAS_CXX23
-#pragma message(_WARNING_MESSAGE("STL4038", "The contents of <stdatomic.h> are available only with C++23 or later."))
+_EMIT_STL_WARNING(STL4038, "The contents of <stdatomic.h> are available only with C++23 or later.");
 #else // ^^^ !_HAS_CXX23 / _HAS_CXX23 vvv
 
 #include <atomic>
diff --git a/stl/inc/stop_token b/stl/inc/stop_token
index d227ff664..39152a0ed 100644
--- a/stl/inc/stop_token
+++ b/stl/inc/stop_token
@@ -10,7 +10,7 @@
 #if _STL_COMPILER_PREPROCESSOR
 
 #if !_HAS_CXX20
-#pragma message(_WARNING_MESSAGE("STL4038", "The contents of <stop_token> are available only with C++20 or later."))
+_EMIT_STL_WARNING(STL4038, "The contents of <stop_token> are available only with C++20 or later.");
 #else // ^^^ !_HAS_CXX20 / _HAS_CXX20 vvv
 
 #include <atomic>
diff --git a/stl/inc/string_view b/stl/inc/string_view
index f08037717..81f80a9a4 100644
--- a/stl/inc/string_view
+++ b/stl/inc/string_view
@@ -10,7 +10,7 @@
 #if _STL_COMPILER_PREPROCESSOR
 
 #if !_HAS_CXX17
-#pragma message(_WARNING_MESSAGE("STL4038", "The contents of <string_view> are available only with C++17 or later."))
+_EMIT_STL_WARNING(STL4038, "The contents of <string_view> are available only with C++17 or later.");
 #else // ^^^ !_HAS_CXX17 / _HAS_CXX17 vvv
 #include <xstring>
 #endif // _HAS_CXX17
diff --git a/stl/inc/syncstream b/stl/inc/syncstream
index 154780a79..70c1e37dc 100644
--- a/stl/inc/syncstream
+++ b/stl/inc/syncstream
@@ -9,7 +9,7 @@
 #include <yvals.h>
 #if _STL_COMPILER_PREPROCESSOR
 #if !_HAS_CXX20
-#pragma message(_WARNING_MESSAGE("STL4038", "The contents of <syncstream> are available only with C++20 or later."))
+_EMIT_STL_WARNING(STL4038, "The contents of <syncstream> are available only with C++20 or later.");
 #else // ^^^ !_HAS_CXX20 / _HAS_CXX20 vvv
 #include <memory>
 #include <ostream>
diff --git a/stl/inc/variant b/stl/inc/variant
index 84e58a815..fe298f290 100644
--- a/stl/inc/variant
+++ b/stl/inc/variant
@@ -10,7 +10,7 @@
 #if _STL_COMPILER_PREPROCESSOR
 
 #if !_HAS_CXX17
-#pragma message(_WARNING_MESSAGE("STL4038", "The contents of <variant> are available only with C++17 or later."))
+_EMIT_STL_WARNING(STL4038, "The contents of <variant> are available only with C++17 or later.");
 #else // ^^^ !_HAS_CXX17 / _HAS_CXX17 vvv
 #include <exception>
 #include <initializer_list>
diff --git a/stl/inc/yvals.h b/stl/inc/yvals.h
index 49fa0599c..4a61dee0b 100644
--- a/stl/inc/yvals.h
+++ b/stl/inc/yvals.h
@@ -233,7 +233,7 @@ _STL_DISABLE_CLANG_WARNINGS
 #ifdef _STATIC_CPPLIB
 #ifndef _DISABLE_DEPRECATE_STATIC_CPPLIB
 #ifdef _DLL
-#pragma message(_WARNING_MESSAGE("STL4000", "_STATIC_CPPLIB is deprecated and will be REMOVED."))
+_EMIT_STL_WARNING(STL4000, "_STATIC_CPPLIB is deprecated and will be REMOVED.");
 #endif
 #ifdef _M_CEE_MIXED
 #error _STATIC_CPPLIB is not supported while building with /clr
@@ -245,7 +245,7 @@ _STL_DISABLE_CLANG_WARNINGS
 #endif // _STATIC_CPPLIB
 
 #if defined(_M_CEE_PURE) && !defined(_SILENCE_CLR_PURE_DEPRECATION_WARNING)
-#pragma message(_WARNING_MESSAGE("STL4001", "/clr:pure is deprecated and will be REMOVED."))
+_EMIT_STL_WARNING(STL4001, "/clr:pure is deprecated and will be REMOVED.");
 #endif
 
 #ifndef _MRTIMP2_PURE
diff --git a/stl/inc/yvals_core.h b/stl/inc/yvals_core.h
index 789c661ab..dfe6cdfa9 100644
--- a/stl/inc/yvals_core.h
+++ b/stl/inc/yvals_core.h
@@ -19,8 +19,14 @@
 
 #if _STL_COMPILER_PREPROCESSOR
 
+// This does not use `_EMIT_STL_ERROR`, as it needs to be checked before we include anything else.
+// However, `_EMIT_STL_ERROR` has a dependency on `_CRT_STRINGIZE`, defined in `<vcruntime.h>`.
+// Here, we employ the same technique as `_CRT_STRINGIZE` in order to avoid needing to update the line number.
 #ifndef __cplusplus
-#error STL1003: Unexpected compiler, expected C++ compiler.
+#define _STL_STRINGIZE_(S) #S
+#define _STL_STRINGIZE(S)  _STL_STRINGIZE_(S)
+#pragma message(__FILE__ "(" _STL_STRINGIZE(__LINE__) "): STL1003: Unexpected compiler, expected C++ compiler.")
+#error Error in C++ Standard Library usage
 #endif // __cplusplus
 
 // Implemented unconditionally:
@@ -417,7 +423,25 @@
 #include <vcruntime.h>
 #include <xkeycheck.h> // The _HAS_CXX tags must be defined before including this.
 
-#define _WARNING_MESSAGE(NUMBER, MESSAGE) __FILE__ "(" _CRT_STRINGIZE(__LINE__) "): warning " NUMBER ": " MESSAGE
+// Note that _STL_PRAGMA is load-bearing;
+// it still needs to exist even once CUDA and ICC support _Pragma.
+#if defined(__CUDACC__) || defined(__INTEL_COMPILER)
+#define _STL_PRAGMA(PRAGMA) __pragma(PRAGMA)
+#else
+#define _STL_PRAGMA(PRAGMA) _Pragma(#PRAGMA)
+#endif
+
+#define _STL_PRAGMA_MESSAGE(MESSAGE) _STL_PRAGMA(message(MESSAGE))
+#define _EMIT_STL_MESSAGE(MESSAGE)   _STL_PRAGMA_MESSAGE(__FILE__ "(" _CRT_STRINGIZE(__LINE__) "): " MESSAGE)
+
+// clang-format off
+#define _EMIT_STL_WARNING(NUMBER, MESSAGE) \
+    _EMIT_STL_MESSAGE("warning " #NUMBER ": " MESSAGE) \
+    static_assert(true, "")
+#define _EMIT_STL_ERROR(NUMBER, MESSAGE) \
+    _EMIT_STL_MESSAGE("error " #NUMBER ": " MESSAGE) \
+    static_assert(false, "Error in C++ Standard Library usage.")
+// clang-format on
 
 #ifndef _STL_WARNING_LEVEL
 #if defined(_MSVC_WARNING_LEVEL) && _MSVC_WARNING_LEVEL >= 4
@@ -620,17 +644,17 @@
 #ifndef _ALLOW_COMPILER_AND_STL_VERSION_MISMATCH
 #if defined(__CUDACC__) && defined(__CUDACC_VER_MAJOR__)
 #if __CUDACC_VER_MAJOR__ < 11 || (__CUDACC_VER_MAJOR__ == 11 && __CUDACC_VER_MINOR__ < 6)
-#error STL1002: Unexpected compiler version, expected CUDA 11.6 or newer.
+_EMIT_STL_ERROR(STL1002, "Unexpected compiler version, expected CUDA 11.6 or newer.");
 #endif // ^^^ old CUDA ^^^
 #elif defined(__EDG__)
 // not attempting to detect __EDG_VERSION__ being less than expected
 #elif defined(__clang__)
 #if __clang_major__ < 14
-#error STL1000: Unexpected compiler version, expected Clang 14.0.0 or newer.
+_EMIT_STL_ERROR(STL1000, "Unexpected compiler version, expected Clang 14.0.0 or newer.");
 #endif // ^^^ old Clang ^^^
 #elif defined(_MSC_VER)
 #if _MSC_VER < 1933 // Coarse-grained, not inspecting _MSC_FULL_VER
-#error STL1001: Unexpected compiler version, expected MSVC 19.33 or newer.
+_EMIT_STL_ERROR(STL1001, "Unexpected compiler version, expected MSVC 19.33 or newer.");
 #endif // ^^^ old MSVC ^^^
 #else // vvv other compilers vvv
 // not attempting to detect other compilers
@@ -687,7 +711,7 @@
 #endif // _HAS_UNEXPECTED
 
 #if _HAS_UNEXPECTED && _HAS_CXX23
-#error STL1004: C++98 unexpected() is incompatible with C++23 unexpected<E>.
+_EMIT_STL_ERROR(STL1004, "C++98 unexpected() is incompatible with C++23 unexpected<E>.");
 #endif // _HAS_UNEXPECTED && _HAS_CXX23
 
 // P0004R1 Removing Deprecated Iostreams Aliases