[[sec:cpp_introduction]]
== Introduction

The simplest build script for a {cpp} project applies the {cpp} application plugin or the {cpp} library plugin and optionally sets the project version:

.Applying the {cpp} Plugin
====

        }
    }
    components {
        main(NativeExecutableSpec) {
            sources {
                cpp.lib library: 'hello'
            }
        }
        mainStatic(NativeExecutableSpec) {
            sources {
                cpp {
                    source.srcDir "src/main/cpp"
                    lib library: 'hello', linkage: 'static'
                }
            }
        }
    }
}

        given:
        buildFile << """
            apply plugin: 'cpp-library'
        """

        def lib = new CppLib()
        lib.writeToProject(testDirectory)
        file('src/main/public/ignore.cpp') << 'broken!'
        file('src/main/headers/ignore.cpp') << 'broken!'
        file('src/main/cpp/ignore.h') << 'broken!'
        file('src/main/cpp/ignore.swift') << 'broken!'

        when:
        succeeds("xcode")

        and:
        buildFile << """
apply plugin: "cpp"
model {
    components {
        main(NativeExecutableSpec) {
            sources {
                cpp.lib library: "hello"
                cpp.lib library: "greetings", linkage: "static"
            }
        }
        hello(NativeLibrarySpec) {
            sources {
                cpp.lib library: "greetings", linkage: "static"
            }

                apply plugin: 'cpp-library'
            }
            project(':app') {
                apply plugin: 'cpp-application'
            }
        """

        file("app/src/main/cpp/main.cpp") << "// main"
        file("lib/src/main/cpp/lib.cpp") << "// lib"

        run("generateSwiftPmManifest")

        assert file("Package.swift").text.contains('"src/main/cpp/main.cpp"')

        given:
        buildFile << """
apply plugin: "cpp"
model {
    components {
        main(NativeLibrarySpec)
    }
}
"""

        and:
        file("src/main/cpp/hello1.cpp") << """
            void hello() {
            }
"""

        and:
        file("src/main/cpp/hello2.cpp") << """
            void hello() {
            }
"""

        when:

        """
        buildFile << """
            project(":exe") {
                apply plugin: "cpp"
                model {
                    components {
                        main(NativeExecutableSpec) {
                            sources {
                                cpp.lib project: ':lib', library: 'hello'
                            }
                        }
                    }

        main.parsedPom.scopes.isEmpty()

        def mainMetadata = main.parsedModuleMetadata
        mainMetadata.variants.size() == 5
        def api = mainMetadata.variant("api")
        api.dependencies.empty
        api.files.size() == 1
        api.files[0].name == 'cpp-api-headers.zip'
        api.files[0].url == 'test-1.2-cpp-api-headers.zip'

        final projectFile = new ProjectFile(file("helloTestExe.vcxproj"))
        projectFile.sourceFiles as Set == [
                "build.gradle",
                "src/helloTest/cpp/test.cpp",
                "src/hello/cpp/hello.cpp",
                "src/hello/cpp/sum.cpp"
        ] as Set
        projectFile.headerFiles == [
                "src/hello/headers/common.h",
                "src/hello/headers/hello.h"
        ]

        given:
        buildFile << """
apply plugin: "cpp"

model {
    components {
        main(NativeExecutableSpec) {
            binaries.all {
                cppCompiler.define 'ENABLE_GREETING'
            }
        }
    }
}
"""

        and:
        file("src/main/cpp/helloworld.cpp") << """
            #include <iostream>

            int main () {