1 files changed, 68 insertions, 0 deletions
diff --git a/StringTools/src/CharTools.cpp b/StringTools/src/CharTools.cpp
new file mode 100644
index 0000000..6484da9
--- /dev/null
+++ b/StringTools/src/CharTools.cpp
@@ -0,0 +1,68 @@
+#include "StringTools/CharTools.h"
+#include <algorithm>
+
+bool CharTools::IsVowel(const char c, const std::string &vowels) {
+    const char lc = MakeLower(c);
+
+    return std::any_of(
+            vowels.cbegin(),
+            vowels.cend(),
+            [lc](const char vowel) {
+                return lc == vowel;
+            }
+    );
+}
+
+bool CharTools::IsLetter(const char c) {
+    // Re-implementing IsUpper and MakeLower to prevent stack-overflow by endless recursion
+    const char lowercase_c = !(c & (1<<5)) ? (c | (1<<5)) : c;
+
+    return (lowercase_c >= 'a') && (lowercase_c <= 'z');
+}
+
+bool CharTools::IsDigit(const char c) {
+    return (c >= '0') && (c <= '9');
+}
+
+bool CharTools::IsUpper(const char c) {
+    if (!IsLetter(c))
+        return false;
+    else
+        return !(c & (1<<5));
+}
+
+bool CharTools::IsLower(const char c) {
+    // Can't just return !IsUpper(c), because it should still return false for digits and symbols...
+
+    if (!IsLetter(c))
+        return false;
+    else
+        return (c & (1<<5));
+}
+
+char CharTools::MakeUpper(char c) {
+    if (!IsLetter(c))
+        return c;
+    else if (IsUpper(c))
+        return c;
+    else
+        return c & ~(1<<5);
+}
+
+char CharTools::MakeLower(char c) {
+    if (!IsLetter(c))
+        return c;
+    else if (!IsUpper(c))
+        return c;
+    else
+        return c | (1<<5);
+}
+
+char CharTools::CopySign(char sign, char c) {
+    if ((!IsLetter(c)) || (!IsLetter(sign)))
+        return c;
+    if (IsUpper(sign))
+        return MakeUpper(c);
+    else
+        return MakeLower(c);
+}