lib/gcrypt/MD5: return a StringBuffer

src/input/plugins/QobuzClient.cxx

@@ -213,7 +213,7 @@ QobuzClient::MakeSignedUrl(const char *object, const char *method,
 	concatenated_query += app_secret;
 
 	const auto md5_hex = MD5Hex({concatenated_query.data(), concatenated_query.size()});
-	q(uri, "request_sig", &md5_hex.front());
+	q(uri, "request_sig", md5_hex);
 
 	return uri;
 }

src/lib/gcrypt/MD5.cxx

@@ -38,13 +38,13 @@ MD5(ConstBuffer<void> input) noexcept
 	return Gcrypt::Hash<GCRY_MD_MD5, 16>(input);
 }
 
-std::array<char, 33>
+StringBuffer<33>
 MD5Hex(ConstBuffer<void> input) noexcept
 {
 	const auto raw = MD5(input);
-	std::array<char, 33> result;
+	StringBuffer<33> result;
 
-	char *p = &result.front();
+	char *p = result.data();
 	for (const auto i : raw) {
 		sprintf(p, "%02x", i);
 		p += 2;

src/lib/gcrypt/MD5.hxx

@@ -30,6 +30,7 @@
 #ifndef GCRYPT_MD5_HXX
 #define GCRYPT_MD5_HXX
 
+#include "util/StringBuffer.hxx"
 #include "Compiler.h"
 
 #include <array>
@@ -41,7 +42,7 @@ std::array<uint8_t, 16>
 MD5(ConstBuffer<void> input) noexcept;
 
 gcc_pure
-std::array<char, 33>
+StringBuffer<33>
 MD5Hex(ConstBuffer<void> input) noexcept;
 
 #endif