Working constexpr that fails compile on invalid.

If you use something the constexpr ANSIColor
doesn't understand it won't compile if you
use constexpr before the ANSIColor variable
declaration.

ansicolor.h

@@ -3,6 +3,7 @@
 
 #include <cstdint>
 #include <string>
+#include <stdexcept>
 
 #define CSI "\x1b["
 
@@ -58,6 +59,7 @@ constexpr long strhash(const char *txt) {
   for (int x = 0; x < 3; ++x) {
     if (txt[x] == 0) break;
     char c = txt[x];
+    // toupper
     if ((c >= 'a') && (c <= 'z')) c &= ~0x20;
     result = (result << 8) | c;
   }
@@ -85,7 +87,6 @@ class ANSIColor {
   COLOR fg;
   /** Background color */
   COLOR bg;
-
   int attr;
 
  public:
@@ -184,6 +185,8 @@ class ANSIColor {
           else
             fg = COLOR::WHITE;
           break;
+        default:
+          throw std::range_error("Invalid/unknown color or attribute");
       }
 
       // skip to the space character

director.cpp

@@ -967,8 +967,8 @@ void Director::macro_have_input(void) {
       char c = toupper(id->input[0]);
       macro_item.assign(1, c);
       if (galaxy.meta["macros"].contains(macro_item)) {
-        ANSIColor key(COLOR::GREEN, ATTR::BOLD);
-        ANSIColor value(COLOR::BLUE, ATTR::BOLD);
+        constexpr ANSIColor key("BOLD GREEN"); // COLOR::GREEN, ATTR::BOLD);
+        constexpr ANSIColor value("BOLD BLUE"); // COLOR::BLUE, ATTR::BOLD);
         std::string output =
             str(boost::format("%1%%2% : %3%%4%\n\r") % key() % macro_item %
                 value() % galaxy.meta["macros"][macro_item]);