Bob 3: one iteration through a string

cpp/bob/bob.cpp

@@ -7,47 +7,32 @@
 namespace bob {
 
 
-using namespace std;
-
-namespace {
-
-void trim_spaces(string &str)
-{
-    str.erase(remove_if(str.begin(), str.end(),
-                        [](char c){return isspace(static_cast<unsigned char>(c));}),
-              str.end());
-}
-
-string to_uppercase(const string &str)
-{
-    string result = str;
-    for (auto & c: result)
-        c = toupper(c);
-
-    return result;
-}
-
-bool has_alpha(const string &str)
-{
-    return find_if(str.begin(), str.end(),
-            [](char c){return isalpha(static_cast<unsigned char>(c));}) != str.end();
-}
-
-}
-
 const char * hey(const char input[])
 {
+    using namespace std;
 
-    string str(input);
-    trim_spaces(str);
+    const string str(input);
 
-    if (str.empty())
+    string::const_reverse_iterator i;
+
+    i = find_if(str.crbegin(), str.crend(), [](char c){return !isspace(c);});
+
+    if (i == str.crend())
         return "Fine. Be that way!";
 
-    if (has_alpha(str) && str == to_uppercase(str))
+    bool is_question = *i == '?';
+
+    i = find_if(i, str.crend(), [](char c){return isalpha(c);});
+
+    bool has_alpha = i != str.crend();
+
+    bool is_uppercase = all_of(i, str.crend(),
+            [](char c){return isupper(c) || !isalpha(c);});
+
+    if (has_alpha && is_uppercase)
         return "Whoa, chill out!";
 
-    if ('?' == str.back())
+    if (is_question)
         return "Sure.";
 
     return "Whatever.";

cpp/bob/bob.h

@@ -1,8 +1,8 @@
 #pragma once
 
-#define EXERCISM_RUN_ALL_TESTS true
+#define EXERCISM_RUN_ALL_TESTS
 
 namespace bob
 {
-    const char * hey(const char str[]);
+    const char * hey(const char input[]);
 }