If you’re building any kind of version management system in C++, such as a package manager or plugin system, then you’ll need to be able to manipulate, compare and print version strings. The Version structure below extracted from pacm does exactly that:
#include <cstdio> #include <string> #include <iostream> struct Version { int major = 0, minor = 0, revision = 0, build = 0; Version(std::string version) { std::sscanf(version.c_str(), "%d.%d.%d.%d", &major, &minor, &revision, &build); } bool operator < (const Version& other) { if (major < other.major) return true; if (minor < other.minor) return true; if (revision < other.revision) return true; if (build < other.build) return true; return false; } bool operator == (const Version& other) { return major == other.major && minor == other.minor && revision == other.revision && build == other.build; } friend std::ostream& operator << (std::ostream& stream, const Version& ver) { stream << ver.major; stream << '.'; stream << ver.minor; stream << '.'; stream << ver.revision; stream << '.'; stream << ver.build; return stream; } };
Example usage:
void testVersionStringComparison() { assert((Version("3.7.8.0") == Version("3.7.8.0")) == true); assert((Version("3.7.8.0") == Version("3.7.8")) == true); assert((Version("3.7.8.0") < Version("3.7.8")) == false); assert((Version("3.7.9") < Version("3.7.8")) == false); assert((Version("3") < Version("3.7.9")) == true); assert((Version("1.7.9") < Version("3.1")) == true); std::cout << "Printing version (3.7.8.0): " << Version("3.7.8.0") << std::endl; }