Fix remaining clang-tidy warnings

* cppcoreguidelines-pro-bounds-array-to-pointer-decay

* modernize-use-auto

include/upa/idna/idna_table.h

@@ -97,7 +97,8 @@ inline std::size_t apply_mapping(uint32_t val, StrT& output) {
             len += ind >> 8;
             ind &= 0xFF;
         }
-        output.append(allCharsTo + ind, allCharsTo + ind + len);
+        const auto* ptr = static_cast<const char32_t*>(allCharsTo) + ind;
+        output.append(ptr, len);
         return len;
     }
     return 0;

src/nfc_table.h

@@ -69,7 +69,7 @@ inline std::size_t get_composition_len(std::uint16_t ci) {
 }
 
 inline const codepoint_key_val* get_composition_data(std::uint16_t ci) {
-    return comp_block_data + (ci & 0x7FF);
+    return static_cast<const codepoint_key_val*>(comp_block_data) + (ci & 0x7FF);
 }
 
 // Decomposition data
@@ -87,7 +87,7 @@ inline std::size_t get_decomposition_len(std::uint16_t di) {
 }
 
 inline const char32_t* get_decomposition_chars(std::uint16_t di) {
-    return decomp_block_data + (di & 0xFFF);
+    return static_cast<const char32_t*>(decomp_block_data) + (di & 0xFFF);
 }
 
 } // namespace normalize

src/punycode.cpp

@@ -205,7 +205,7 @@ status decode(std::u32string& output, const char32_t* first, const char32_t* las
     // Initialize the state:
 
     punycode_uint n = initial_n;
-    punycode_uint out = static_cast<punycode_uint>(output.length() - len0); // basic code points count
+    auto out = static_cast<punycode_uint>(output.length() - len0); // basic code points count
     punycode_uint i = 0;
     punycode_uint bias = initial_bias;