fix find_last_of when char isn't found (#49)

resolves #48

include/cib/detail/find.hpp

@@ -32,17 +32,20 @@ namespace cib::detail {
             }
         }
 
-        return str.size();
+        return 0;
     }
 
     // clang-8 and below don't have constexpr find_last_of on std::string_view
     CIB_CONSTEVAL std::string_view::size_type find_last_of(std::string_view str, char c) {
         using size_type = std::string_view::size_type;
-        for (size_type i = str.size() - 1; true; i--) {
+        size_type match = str.size();
+        for (size_type i = 0; i < str.size(); i++) {
             if (str[i] == c) {
-                return i;
+                match = i;
             }
         }
+
+        return match;
     }
 
     template<typename Tag>

test/CMakeLists.txt

@@ -9,6 +9,7 @@ add_executable(tests
     callback.cpp
     nexus.cpp
     detail/ordered_set.cpp
+    readme_hello_world.cpp
 )
 
 if (CMAKE_CXX_COMPILER_ID STREQUAL "Clang")

test/readme_hello_world.cpp

@@ -0,0 +1,34 @@
+#include <cib/cib.hpp>
+
+#include <catch2/catch_test_macros.hpp>
+
+#include <cstdio>
+
+struct say_message : public cib::callback_meta<>{};
+
+// the 'core' component exposes the 'say_message' service for others to extend
+struct core {
+    constexpr static auto config = cib::exports<say_message>;
+};
+
+// the 'say_hello_world' component extends 'say_message' with its own functionality
+struct say_hello_world {
+    constexpr static auto config =
+        cib::extend<say_message>([](){
+            puts("Hello, world!\n");
+        });
+};
+
+// the 'hello_world' project composes 'core' and 'say_hello_world'
+struct hello_world {
+    constexpr static auto config =
+        cib::components<core, say_hello_world>;
+};
+
+// the nexus instantiates the project
+cib::nexus<hello_world> nexus{};
+
+
+TEST_CASE("make sure the simple hello world example compiles") {
+    nexus.service<say_message>();
+}