parse/value: add bool specialisation

parse/value.cpp

@@ -152,3 +152,34 @@ C_PARSE_WITH_CAST(short, long)
 C_PARSE_WITH_CAST(int,   long)
 C_PARSE_WITH_CAST(unsigned short, unsigned long)
 C_PARSE_WITH_CAST(unsigned int,   unsigned long)
+
+
+///////////////////////////////////////////////////////////////////////////////
+template <>
+bool
+cruft::parse::value<bool> (cruft::view<char const*> &str)
+{
+    static constexpr struct {
+        char const *str;
+        bool res;
+    } VALUES[] = {
+        { "yes", true },
+        { "y",   true },
+        { "true",true },
+        { "t",   true },
+
+        { "no",     false, },
+        { "n",      false, },
+        { "false",  false, },
+        { "f",      false, },
+    };
+
+    for (auto [key,val]: VALUES) {
+        if (equal (key, str)) {
+            str = str.consume (strlen (key));
+            return val;
+        }
+    }
+
+    throw std::invalid_argument ("invalid boolean string");
+}

test/parse/value.cpp

@@ -14,5 +14,8 @@ main (void)
     tap.expect_eq (cruft::parse::from_string<float> ("1"), 1.f, "parsing float '1'");
     tap.expect_throw<std::invalid_argument> ([] () { cruft::parse::from_string<float> ("a"); }, "parsing float 'a'");
 
+    tap.expect_eq (cruft::parse::from_string<bool> ("true"), true, "parsing true");
+    tap.expect_eq (cruft::parse::from_string<bool> ("false"), false, "parsing false");
+
     return tap.status ();
 }