tag/VorbisComment: use std::string_view

src/lib/xiph/ScanVorbisComment.cxx

@@ -29,12 +29,12 @@
  * the comment value into the tag.
  */
 static bool
-vorbis_copy_comment(StringView comment,
-		    StringView name, TagType tag_type,
+vorbis_copy_comment(std::string_view comment,
+		    std::string_view name, TagType tag_type,
 		    TagHandler &handler) noexcept
 {
 	const auto value = GetVorbisCommentValue(comment, name);
-	if (!value.IsNull()) {
+	if (value.data() != nullptr) {
 		handler.OnTag(tag_type, value);
 		return true;
 	}

src/lib/xiph/VorbisComments.cxx

@@ -68,8 +68,8 @@ vorbis_scan_comment(StringView comment, TagHandler &handler) noexcept
 {
 	const auto picture_b64 = handler.WantPicture()
 		? GetVorbisCommentValue(comment, "METADATA_BLOCK_PICTURE")
-		: nullptr;
-	if (!picture_b64.IsNull())
+		: std::string_view{};
+	if (picture_b64.data() != nullptr)
 		return ScanVorbisPicture(picture_b64, handler);
 
 	ScanVorbisComment(comment, handler);

src/tag/ReplayGainParser.cxx

@@ -75,11 +75,11 @@ bool
 ParseReplayGainVorbis(ReplayGainInfo &info, StringView entry) noexcept
 {
 	struct VorbisCommentEntry {
-		StringView entry;
+		std::string_view entry;
 
 		gcc_pure
-		const char *operator[](StringView n) const noexcept {
-			return GetVorbisCommentValue(entry, n).data;
+		const char *operator[](std::string_view n) const noexcept {
+			return GetVorbisCommentValue(entry, n).data();
 		}
 	};
 

src/tag/VorbisComment.cxx

@@ -18,21 +18,19 @@
  */
 
 #include "VorbisComment.hxx"
-#include "util/StringView.hxx"
+#include "util/StringCompare.hxx"
 
 #include <cassert>
 
-StringView
-GetVorbisCommentValue(StringView entry, StringView name) noexcept
+std::string_view
+GetVorbisCommentValue(std::string_view entry, std::string_view name) noexcept
 {
 	assert(!name.empty());
 
-	if (entry.StartsWithIgnoreCase(name) &&
-	    entry.size > name.size &&
-	    entry[name.size] == '=') {
-		entry.skip_front(name.size + 1);
-		return entry;
-	}
+	if (StringStartsWithIgnoreCase(entry, name) &&
+	    entry.size() > name.size() &&
+	    entry[name.size()] == '=')
+		return entry.substr(name.size() + 1);
 
-	return nullptr;
+	return {};
 }

src/tag/VorbisComment.hxx

@@ -20,14 +20,14 @@
 #ifndef MPD_TAG_VORBIS_COMMENT_HXX
 #define MPD_TAG_VORBIS_COMMENT_HXX
 
-struct StringView;
+#include <string_view>
 
 /**
  * Checks if the specified name matches the entry's name, and if yes,
  * returns the comment value.
  */
 [[gnu::pure]]
-StringView
-GetVorbisCommentValue(StringView entry, StringView name) noexcept;
+std::string_view
+GetVorbisCommentValue(std::string_view entry, std::string_view name) noexcept;
 
 #endif