1 files changed, 10 insertions, 11 deletions
diff --git a/cores/arduino/WString.cpp b/cores/arduino/WString.cpp
index 8b6eabe..ed880ce 100644
--- a/cores/arduino/WString.cpp
+++ b/cores/arduino/WString.cpp
@@ -21,7 +21,6 @@
 
 #include "WString.h"
 
-
 /*********************************************/
 /*  Constructors                             */
 /*********************************************/
@@ -69,7 +68,7 @@ String::String(char c)
 String::String(unsigned char value, unsigned char base)
 {
 	init();
-	char buf[9];
+	char buf[1 + 8 * sizeof(unsigned char)];
 	utoa(value, buf, base);
 	*this = buf;
 }
@@ -77,7 +76,7 @@ String::String(unsigned char value, unsigned char base)
 String::String(int value, unsigned char base)
 {
 	init();
-	char buf[18];
+	char buf[2 + 8 * sizeof(int)];
 	itoa(value, buf, base);
 	*this = buf;
 }
@@ -85,7 +84,7 @@ String::String(int value, unsigned char base)
 String::String(unsigned int value, unsigned char base)
 {
 	init();
-	char buf[17];
+	char buf[1 + 8 * sizeof(unsigned int)];
 	utoa(value, buf, base);
 	*this = buf;
 }
@@ -93,7 +92,7 @@ String::String(unsigned int value, unsigned char base)
 String::String(long value, unsigned char base)
 {
 	init();
-	char buf[34];
+	char buf[2 + 8 * sizeof(long)];
 	ltoa(value, buf, base);
 	*this = buf;
 }
@@ -101,7 +100,7 @@ String::String(long value, unsigned char base)
 String::String(unsigned long value, unsigned char base)
 {
 	init();
-	char buf[33];
+	char buf[1 + 8 * sizeof(unsigned long)];
 	ultoa(value, buf, base);
 	*this = buf;
 }
@@ -288,35 +287,35 @@ unsigned char String::concat(char c)
 
 unsigned char String::concat(unsigned char num)
 {
-	char buf[4];
+	char buf[1 + 3 * sizeof(unsigned char)];
 	itoa(num, buf, 10);
 	return concat(buf, strlen(buf));
 }
 
 unsigned char String::concat(int num)
 {
-	char buf[12];
+	char buf[2 + 3 * sizeof(int)];
 	itoa(num, buf, 10);
 	return concat(buf, strlen(buf));
 }
 
 unsigned char String::concat(unsigned int num)
 {
-	char buf[11];
+	char buf[1 + 3 * sizeof(unsigned int)];
 	utoa(num, buf, 10);
 	return concat(buf, strlen(buf));
 }
 
 unsigned char String::concat(long num)
 {
-	char buf[12];
+	char buf[2 + 3 * sizeof(long)];
 	ltoa(num, buf, 10);
 	return concat(buf, strlen(buf));
 }
 
 unsigned char String::concat(unsigned long num)
 {
-	char buf[11];
+	char buf[1 + 3 * sizeof(unsigned long)];
 	ultoa(num, buf, 10);
 	return concat(buf, strlen(buf));
 }