[c++14] Remove C++11 compatibility macros (#30296)

src/core/ext/transport/chttp2/transport/hpack_parser.cc

@@ -59,14 +59,6 @@
 
 // IWYU pragma: no_include <type_traits>
 
-#if __cplusplus > 201103L
-#define GRPC_HPACK_CONSTEXPR_FN constexpr
-#define GRPC_HPACK_CONSTEXPR_VALUE constexpr
-#else
-#define GRPC_HPACK_CONSTEXPR_FN
-#define GRPC_HPACK_CONSTEXPR_VALUE const
-#endif
-
 namespace grpc_core {
 
 TraceFlag grpc_trace_chttp2_hpack_parser(false, "chttp2_hpack_parser");
@@ -454,7 +446,7 @@ constexpr char kBase64Alphabet[] =
 // any complicated runtime logic.
 struct Base64InverseTable {
   uint8_t table[256]{};
-  GRPC_HPACK_CONSTEXPR_FN Base64InverseTable() {
+  constexpr Base64InverseTable() {
     for (int i = 0; i < 256; i++) {
       table[i] = 255;
     }
@@ -466,7 +458,7 @@ struct Base64InverseTable {
   }
 };
 
-GRPC_HPACK_CONSTEXPR_VALUE Base64InverseTable kBase64InverseTable;
+constexpr Base64InverseTable kBase64InverseTable;
 }  // namespace
 
 // Input tracks the current byte through the input data and provides it

src/core/lib/surface/validate_metadata.cc

@@ -29,14 +29,6 @@
 #include "src/core/lib/gprpp/memory.h"
 #include "src/core/lib/iomgr/error.h"
 
-#if __cplusplus > 201103l
-#define GRPC_VALIDATE_METADATA_CONSTEXPR_FN constexpr
-#define GRPC_VALIDATE_METADATA_CONSTEXPR_VALUE constexpr
-#else
-#define GRPC_VALIDATE_METADATA_CONSTEXPR_FN
-#define GRPC_VALIDATE_METADATA_CONSTEXPR_VALUE const
-#endif
-
 static grpc_error_handle conforms_to(const grpc_slice& slice,
                                      const grpc_core::BitSet<256>& legal_bits,
                                      const char* err_desc) {
@@ -68,7 +60,7 @@ static int error2int(grpc_error_handle error) {
 namespace {
 class LegalHeaderKeyBits : public grpc_core::BitSet<256> {
  public:
-  GRPC_VALIDATE_METADATA_CONSTEXPR_FN LegalHeaderKeyBits() {
+  constexpr LegalHeaderKeyBits() {
     for (int i = 'a'; i <= 'z'; i++) set(i);
     for (int i = '0'; i <= '9'; i++) set(i);
     set('-');
@@ -76,8 +68,7 @@ class LegalHeaderKeyBits : public grpc_core::BitSet<256> {
     set('.');
   }
 };
-GRPC_VALIDATE_METADATA_CONSTEXPR_VALUE LegalHeaderKeyBits
-    g_legal_header_key_bits;
+constexpr LegalHeaderKeyBits g_legal_header_key_bits;
 }  // namespace
 
 grpc_error_handle grpc_validate_header_key_is_legal(const grpc_slice& slice) {
@@ -103,14 +94,13 @@ int grpc_header_key_is_legal(grpc_slice slice) {
 namespace {
 class LegalHeaderNonBinValueBits : public grpc_core::BitSet<256> {
  public:
-  GRPC_VALIDATE_METADATA_CONSTEXPR_FN LegalHeaderNonBinValueBits() {
+  constexpr LegalHeaderNonBinValueBits() {
     for (int i = 32; i <= 126; i++) {
       set(i);
     }
   }
 };
-GRPC_VALIDATE_METADATA_CONSTEXPR_VALUE LegalHeaderNonBinValueBits
-    g_legal_header_non_bin_value_bits;
+constexpr LegalHeaderNonBinValueBits g_legal_header_non_bin_value_bits;
 }  // namespace
 
 grpc_error_handle grpc_validate_header_nonbin_value_is_legal(