Basic usage example

Author: williamhaarhoff

CMakeLists.txt

@@ -16,6 +16,7 @@ if (NOT WIN32)
   message(STATUS "Building the example!")
   add_executable(multiinheritance src/multiinheritance.cpp)
   add_executable(mixin_patterns src/mixin_patterns.cpp)
+  add_executable(basic_usage src/basic_usage.cpp)
   install(TARGETS multiinheritance DESTINATION bin)
 endif()
 

src/basic_usage.cpp

@@ -0,0 +1,166 @@
+#include "archetype/archetype.h"
+#include <iostream>
+#include <cstring>
+#include <string>
+#include <vector>
+
+// Define our archetypes
+ARCHETYPE_DEFINE(writable, (
+  ARCHETYPE_METHOD(int, write, const char *, size_t)
+))
+
+ARCHETYPE_DEFINE(readable, (
+  ARCHETYPE_METHOD(int, read, char *, size_t)
+))
+
+ARCHETYPE_COMPOSE(readwritable, readable, writable)
+
+
+
+// Here is a collection of readers and writers created in different ways
+class Writer {
+public:
+  int write(const char *buf, size_t size) {
+    int n = 0;
+    while (size--) { std::cout << buf[n++]; }
+    std::cout << std::flush;
+    return n;
+  }
+};
+
+class Reader {
+public:
+  int read(char *buf, size_t size) { return std::fread(buf, 1, size, stdin); }
+};
+
+class InherritedReadWriter : public Writer {
+public:
+  int read(char *buf, size_t size) { return std::fread(buf, 1, size, stdin); }
+};
+
+class NativeReadWriter {
+public:
+  int read(char *buf, size_t size) { return std::fread(buf, 1, size, stdin); }
+  int write(const char *buf, size_t size) {
+    int n = 0;
+    while (size--) {
+      std::cout << buf[n++];
+    }
+    std::cout << std::flush;
+    return n;
+  }
+};
+
+class ComposedReadWriter {
+public:
+  int read(char *buf, size_t size) { return reader.read(buf, size); }
+  int write(const char *buf, size_t size) { return writer.write(buf, size); }
+
+private:
+  Writer writer;
+  Reader reader;
+};
+
+struct AbstractWriter
+{
+  virtual int write(const char *buf, size_t size) = 0;
+};
+
+struct AbstractReader
+{
+  virtual int read(char *buf, size_t size) = 0;
+};
+
+struct DerivedWriter : public AbstractWriter
+{
+  virtual int write(const char *buf, size_t size) final {
+    int n = 0;
+    while (size--) {
+      std::cout << buf[n++];
+    }
+    std::cout << std::flush;
+    return n;
+  }
+};
+
+struct DerivedReadWriter : public AbstractWriter, public AbstractReader
+{
+  virtual int write(const char *buf, size_t size) final {
+    int n = 0;
+    while (size--) {
+      std::cout << buf[n++];
+    }
+    std::cout << std::flush;
+    return n;
+  }
+  virtual int read(char *buf, size_t size) final {
+    return std::fread(buf, 1, size, stdin);
+  }
+};
+
+// Define interfaces 
+
+
+// Stateless mixin read API
+template <typename R> struct ReadAPI : public R {
+  ARCHETYPE_CHECK(readable, R)
+  using R::R;
+  using R::read;
+  int read_api(char *buf, size_t size) { return this->read(buf, size); }
+};
+
+
+// Stateful mixin APIs
+template <typename  W> struct StatefulWriteAPI : public W {
+  ARCHETYPE_CHECK(writable, W);
+  using W::W;
+  using W::write;
+  size_t write_api(const char *buf) {
+    std::string header = "count: " + std::to_string(count++)+ " ";
+    int size = this->write(header.c_str(), header.size());
+    size += this->write(buf, strlen(buf));
+    return size;
+  }
+  int count = 0;
+};
+
+int main()
+{
+
+  if (__cplusplus == 202302L)
+    std::cout << "C++23";
+  else if (__cplusplus == 202002L)
+    std::cout << "C++20";
+  else if (__cplusplus == 201703L)
+    std::cout << "C++17";
+  else if (__cplusplus == 201402L)
+    std::cout << "C++14";
+  else if (__cplusplus == 201103L)
+    std::cout << "C++11";
+  else if (__cplusplus == 199711L)
+    std::cout << "C++98";
+  else
+    std::cout << "pre-standard C++." << __cplusplus;
+  std::cout << "\n";
+
+
+  ComposedReadWriter composed_read_writer;
+  NativeReadWriter native_read_writer;
+  InherritedReadWriter inherrited_read_writer;
+  AbstractWriter * base_ptr = new DerivedReadWriter();
+  std::vector<writable::view> views(4);
+
+  views[0].bind(composed_read_writer);
+  views[1].bind(native_read_writer);
+  views[2].bind(inherrited_read_writer);
+  views[3].bind(*base_ptr);
+
+  for (auto & view : views) {
+    view.write("hello\r\n", 7);
+  }
+
+
+  delete base_ptr;
+  return 0;
+
+}