Improve C++ example
--
MOS_MIGRATED_REVID=87514947
diff --git a/base_workspace/examples/cpp/README.md b/base_workspace/examples/cpp/README.md
new file mode 100644
index 0000000..fba7143
--- /dev/null
+++ b/base_workspace/examples/cpp/README.md
@@ -0,0 +1,4 @@
+C++ Examples
+============
+
+These examples demonstrate building C++ binaries, libraries, and tests.
diff --git a/base_workspace/examples/cpp/hello-fail.cc b/base_workspace/examples/cpp/hello-fail.cc
index 9b0b94a..5b561cb 100644
--- a/base_workspace/examples/cpp/hello-fail.cc
+++ b/base_workspace/examples/cpp/hello-fail.cc
@@ -1,11 +1,22 @@
#include "examples/cpp/hello-lib.h"
+#include <string>
+
+using hello::HelloLib;
+using std::string;
+
+/**
+ * This is a fake test that prints "Hello barf" and then exits with exit code 1.
+ * If run as a test (cc_test), the non-0 exit code indicates to Bazel that the
+ * "test" has failed.
+ */
int main(int argc, char** argv) {
- const char* obj = "barf";
+ HelloLib lib;
+ string thing = "barf";
if (argc > 1) {
- obj = argv[1];
+ thing = argv[1];
}
- greet(obj);
+ lib.greet(thing);
return 1;
}
diff --git a/base_workspace/examples/cpp/hello-lib.cc b/base_workspace/examples/cpp/hello-lib.cc
index aee43ba..8e40921 100644
--- a/base_workspace/examples/cpp/hello-lib.cc
+++ b/base_workspace/examples/cpp/hello-lib.cc
@@ -1,5 +1,21 @@
#include "examples/cpp/hello-lib.h"
-#include <stdio.h>
+#include <iostream>
-void greet(const char* obj) { printf("hello %s\n", obj); }
+using std::cout;
+using std::endl;
+using std::string;
+
+namespace hello {
+
+HelloLib::HelloLib() : HelloLib("Hello") {
+}
+
+HelloLib::HelloLib(const string& greeting) : greeting_(new string(greeting)) {
+}
+
+void HelloLib::greet(const string& thing) {
+ cout << *greeting_ << " " << thing << endl;
+}
+
+} // namespace hello
diff --git a/base_workspace/examples/cpp/hello-lib.h b/base_workspace/examples/cpp/hello-lib.h
index 3e74c2b..555d177 100644
--- a/base_workspace/examples/cpp/hello-lib.h
+++ b/base_workspace/examples/cpp/hello-lib.h
@@ -1,6 +1,23 @@
-#ifndef EXAMPLE_WORKSPACE_CPP_HELLO_LIB_H_
-#define EXAMPLE_WORKSPACE_CPP_HELLO_LIB_H_
+#ifndef EXAMPLES_CPP_HELLO_LIB_H_
+#define EXAMPLES_CPP_HELLO_LIB_H_
-void greet(const char* object);
+#include <string>
+#include <memory>
-#endif // EXAMPLE_WORKSPACE_CPP_HELLO_LIB_H_
+namespace hello {
+
+class HelloLib {
+ public:
+ HelloLib();
+
+ explicit HelloLib(const std::string &greeting);
+
+ void greet(const std::string &thing);
+
+ private:
+ std::unique_ptr<const std::string> greeting_;
+};
+
+} // namespace hello
+
+#endif // EXAMPLES_CPP_HELLO_LIB_H_
diff --git a/base_workspace/examples/cpp/hello-world.cc b/base_workspace/examples/cpp/hello-world.cc
index 305b17f..be435c3 100644
--- a/base_workspace/examples/cpp/hello-world.cc
+++ b/base_workspace/examples/cpp/hello-world.cc
@@ -1,11 +1,26 @@
#include "examples/cpp/hello-lib.h"
-int main(int argc, char** argv) {
- const char* obj = "world";
- if (argc > 1) {
- obj = argv[1];
- }
+#include <string>
- greet(obj);
+using hello::HelloLib;
+using std::string;
+
+/**
+ * This prints "Hello world". If it is run with arguments, it will use the first
+ * argument instead of "world". Build and run //examples/cpp:hello-world to see
+ * this program in action.
+ *
+ * This file does double-duty as a "test." It is a cc_binary, so it can also be
+ * compiled as a cc_test and Bazel will decide on whether it passed or failed
+ * based on exit code (which is always 0 here, so the test "passes"). See
+ * hello-fail.cc for an example of making a test fail.
+ */
+int main(int argc, char** argv) {
+ HelloLib lib("Hello");
+ string thing = "world";
+ if (argc > 1) {
+ thing = argv[1];
+ }
+ lib.greet(thing);
return 0;
}
