diff --git a/include/helpers.hpp b/include/helpers.hpp
index 67e0eb88..55b40640 100644
--- a/include/helpers.hpp
+++ b/include/helpers.hpp
@@ -93,15 +93,14 @@ static inline int clz(unsigned int x) {
 #define CAT(x, y)            x##y
 #define EXPAND_AND_CAT(x, y) CAT(x, y)
 
-// Obtaining the size of an array; `arr` must be an expression, not a type!
-// (Having two instances of `arr` is OK because the contents of `sizeof` are not evaluated.)
-#define ARRAY_SIZE(arr) (sizeof(arr) / sizeof *(arr))
-
 // For lack of <ranges>, this adds some more brevity
 #define RANGE(s) std::begin(s), std::end(s)
 
-// MSVC does not inline `strlen()` or `.length()` of a constant string, so we use `sizeof`
-#define QUOTEDSTRLEN(s) (sizeof(s) - 1)
+// MSVC does not inline `strlen()` or `.length()` of a constant string
+template<int N>
+static constexpr int literal_strlen(char const (&)[N]) {
+	return N - 1;
+}
 
 // For ad-hoc RAII in place of a `defer` statement or cross-platform `__attribute__((cleanup))`
 template<typename T>
diff --git a/src/asm/lexer.cpp b/src/asm/lexer.cpp
index bd11dd34..9bcbcd1c 100644
--- a/src/asm/lexer.cpp
+++ b/src/asm/lexer.cpp
@@ -500,27 +500,27 @@ BufferedContent::~BufferedContent() {
 }
 
 void BufferedContent::advance() {
-	assume(offset < ARRAY_SIZE(buf));
+	assume(offset < std::size(buf));
 	offset++;
-	if (offset == ARRAY_SIZE(buf))
+	if (offset == std::size(buf))
 		offset = 0; // Wrap around if necessary
 	assume(size > 0);
 	size--;
 }
 
 void BufferedContent::refill() {
-	size_t target = ARRAY_SIZE(buf) - size; // Aim: making the buf full
+	size_t target = std::size(buf) - size; // Aim: making the buf full
 
 	// Compute the index we'll start writing to
-	size_t startIndex = (offset + size) % ARRAY_SIZE(buf);
+	size_t startIndex = (offset + size) % std::size(buf);
 
 	// If the range to fill passes over the buffer wrapping point, we need two reads
-	if (startIndex + target > ARRAY_SIZE(buf)) {
-		size_t nbExpectedChars = ARRAY_SIZE(buf) - startIndex;
+	if (startIndex + target > std::size(buf)) {
+		size_t nbExpectedChars = std::size(buf) - startIndex;
 		size_t nbReadChars = readMore(startIndex, nbExpectedChars);
 
 		startIndex += nbReadChars;
-		if (startIndex == ARRAY_SIZE(buf))
+		if (startIndex == std::size(buf))
 			startIndex = 0;
 
 		// If the read was incomplete, don't perform a second read
@@ -534,7 +534,7 @@ void BufferedContent::refill() {
 
 size_t BufferedContent::readMore(size_t startIndex, size_t nbChars) {
 	// This buffer overflow made me lose WEEKS of my life. Never again.
-	assume(startIndex + nbChars <= ARRAY_SIZE(buf));
+	assume(startIndex + nbChars <= std::size(buf));
 	ssize_t nbReadChars = read(fd, &buf[startIndex], nbChars);
 
 	if (nbReadChars == -1)
@@ -720,7 +720,7 @@ int LexerState::peekChar() {
 		auto &cbuf = content.get<BufferedContent>();
 		if (cbuf.size == 0)
 			cbuf.refill();
-		assume(cbuf.offset < ARRAY_SIZE(cbuf.buf));
+		assume(cbuf.offset < std::size(cbuf.buf));
 		if (cbuf.size > 0)
 			return static_cast<uint8_t>(cbuf.buf[cbuf.offset]);
 	}
@@ -748,11 +748,11 @@ int LexerState::peekCharAhead() {
 			return static_cast<uint8_t>(view.span.ptr[view.offset + distance]);
 	} else {
 		auto &cbuf = content.get<BufferedContent>();
-		assume(distance < ARRAY_SIZE(cbuf.buf));
+		assume(distance < std::size(cbuf.buf));
 		if (cbuf.size <= distance)
 			cbuf.refill();
 		if (cbuf.size > distance)
-			return static_cast<uint8_t>(cbuf.buf[(cbuf.offset + distance) % ARRAY_SIZE(cbuf.buf)]);
+			return static_cast<uint8_t>(cbuf.buf[(cbuf.offset + distance) % std::size(cbuf.buf)]);
 	}
 
 	// If there aren't enough chars, give up
@@ -2339,7 +2339,7 @@ Capture lexer_CaptureRept() {
 					endCapture(capture);
 					// The final ENDR has been captured, but we don't want it!
 					// We know we have read exactly "ENDR", not e.g. an EQUS
-					capture.span.size -= QUOTEDSTRLEN("ENDR");
+					capture.span.size -= literal_strlen("ENDR");
 					return capture;
 				}
 				depth--;
@@ -2385,7 +2385,7 @@ Capture lexer_CaptureMacro() {
 				endCapture(capture);
 				// The ENDM has been captured, but we don't want it!
 				// We know we have read exactly "ENDM", not e.g. an EQUS
-				capture.span.size -= QUOTEDSTRLEN("ENDM");
+				capture.span.size -= literal_strlen("ENDM");
 				return capture;
 
 			default:
diff --git a/src/asm/main.cpp b/src/asm/main.cpp
index 4346a0ac..66713a1c 100644
--- a/src/asm/main.cpp
+++ b/src/asm/main.cpp
@@ -41,7 +41,7 @@ static std::string make_escape(std::string &str) {
 			break;
 		escaped.append(str, pos, nextPos - pos);
 		escaped.append("$$");
-		pos = nextPos + QUOTEDSTRLEN("$");
+		pos = nextPos + literal_strlen("$");
 	}
 	escaped.append(str, pos, str.length() - pos);
 	return escaped;
diff --git a/src/asm/warning.cpp b/src/asm/warning.cpp
index b96b4a08..2288c106 100644
--- a/src/asm/warning.cpp
+++ b/src/asm/warning.cpp
@@ -149,16 +149,16 @@ void processWarningFlag(char const *flag) {
 	if (rootFlag.starts_with("error=")) {
 		// `-Werror=<flag>` enables the flag as an error
 		state = {.state = WARNING_ENABLED, .error = WARNING_ENABLED};
-		rootFlag.erase(0, QUOTEDSTRLEN("error="));
+		rootFlag.erase(0, literal_strlen("error="));
 	} else if (rootFlag.starts_with("no-error=")) {
 		// `-Wno-error=<flag>` prevents the flag from being an error,
 		// without affecting whether it is enabled
 		state = {.state = WARNING_DEFAULT, .error = WARNING_DISABLED};
-		rootFlag.erase(0, QUOTEDSTRLEN("no-error="));
+		rootFlag.erase(0, literal_strlen("no-error="));
 	} else if (rootFlag.starts_with("no-")) {
 		// `-Wno-<flag>` disables the flag
 		state = {.state = WARNING_DISABLED, .error = WARNING_DEFAULT};
-		rootFlag.erase(0, QUOTEDSTRLEN("no-"));
+		rootFlag.erase(0, literal_strlen("no-"));
 	} else {
 		// `-W<flag>` enables the flag
 		state = {.state = WARNING_ENABLED, .error = WARNING_DEFAULT};
diff --git a/src/gfx/process.cpp b/src/gfx/process.cpp
index a80a5033..9aeeb6e6 100644
--- a/src/gfx/process.cpp
+++ b/src/gfx/process.cpp
@@ -623,7 +623,7 @@ static std::tuple<DefaultInitVec<size_t>, std::vector<Palette>>
 		for (uint16_t cgbColor : list) {
 			ptr += snprintf(ptr, sizeof(", $XXXX"), ", $%04x", cgbColor);
 		}
-		return &buf[QUOTEDSTRLEN(", ")];
+		return &buf[literal_strlen(", ")];
 	};
 
 	// Iterate through proto-palettes, and try mapping them to the specified palettes
diff --git a/src/link/object.cpp b/src/link/object.cpp
index 20b4b11b..4253d30d 100644
--- a/src/link/object.cpp
+++ b/src/link/object.cpp
@@ -528,7 +528,7 @@ void obj_ReadFile(char const *fileName, unsigned int fileID) {
 	int matchedElems;
 
 	if (fscanf(file, RGBDS_OBJECT_VERSION_STRING "%n", &matchedElems) == 1
-	    && matchedElems != QUOTEDSTRLEN(RGBDS_OBJECT_VERSION_STRING))
+	    && matchedElems != literal_strlen(RGBDS_OBJECT_VERSION_STRING))
 		errx("%s: Not a RGBDS object file", fileName);
 
 	verbosePrint("Reading object file %s\n", fileName);
diff --git a/src/version.cpp b/src/version.cpp
index 1dec1fcb..1b346677 100644
--- a/src/version.cpp
+++ b/src/version.cpp
@@ -29,7 +29,7 @@ extern "C" {
 #endif
 
 char const *get_package_version_string() {
-	if constexpr (QUOTEDSTRLEN(BUILD_VERSION_STRING) > 0) {
+	if constexpr (literal_strlen(BUILD_VERSION_STRING) > 0) {
 		return BUILD_VERSION_STRING;
 	}
 	// Fallback if version string can't be obtained from Git