C++ Function Benchmark

Benchmark for various C++ function implementations. This project focuses on invocation time.

Currently include:

• stdex::function - A multi-signature function implementation by @jamboree.
• multifunction - Example from Boost.TypeErasure, another multi-signature function.
• std::function - Standard.
• boost::function - The one from Boost.
• func::function - From this blog.
• generic::delegate - Fast delegate in C++11, also see here.
• fastdelegate::FastDelegate - By Don Clugston, see here
• ssvu::FastFunc - Another Don Clugston's FastDelegate, as shown here and here.
• cxx_function::function - By David Krauss
• fu2::function - By Denis Blank
• fixed_size_function - By Pavel Medvedev
• gnr::forwarder - here.
• embxx::util::StaticFunction - By Alex Robenko, see here - either on master or develop branch.
• Function - By Erik Rigtorp, see here
• folly::Function - From Facebook Folly; see here
• bsl::function - From Bloomberg BDE; see here
• stdext::inplace_function - From SG14; see here and here
• Delegate::Func - A non-allocating implementation by Ben Diamand; see here

Sample Result

Compiled with MSVC (64-bit/Visual Studio 15.9.4/Release Build/Boost 1.69.0)

various.cpp

The size of each implementation is shown in the [size] section. Keep in mind that bigger size does not necessarily mean that it's less space efficient, it may due to the decision on how much space is reserved for small object optimization. Other sections show the timing of function invocation for each implementation when assigned different callable objects.

[size]
stdex::function<int(int)>: 24
std::function<int(int)>: 64
cxx_function::function<int(int)>: 40
multifunction<int(int)>: 32
boost::function<int(int)>: 40
func::function<int(int)>: 32
generic::delegate<int(int)>: 48
fu2::function<int(int)>: 32
fixed_size_function<int(int)>: 128
embxx_util_StaticFunction: 64
Function_: 56
inplace_function: 48
Delegate: 56

[function_pointer]
Perf< no_abstraction >: 0.1581233938 [s] {checksum: 0}
Perf< stdex::function<int(int)> >: 0.2369854883 [s] {checksum: 0}
Perf< std::function<int(int)> >: 0.2639573047 [s] {checksum: 0}
Perf< cxx_function::function<int(int)> >: 0.2635273223 [s] {checksum: 0}
Perf< multifunction<int(int)> >: 0.2633797704 [s] {checksum: 0}
Perf< boost::function<int(int)> >: 0.2632382534 [s] {checksum: 0}
Perf< func::function<int(int)> >: 0.2367664236 [s] {checksum: 0}
Perf< generic::delegate<int(int)> >: 0.2370002737 [s] {checksum: 0}
Perf< fu2::function<int(int)> >: 0.2363500196 [s] {checksum: 0}
Perf< fixed_size_function<int(int)> >: 0.2627183519 [s] {checksum: 0}
Perf< embxx_util_StaticFunction >: 0.2630701831 [s] {checksum: 0}
Perf< Function_ >:    0.2629322870 [s] {checksum: 0}
Perf< inplace_function >: 0.2364676990 [s] {checksum: 0}
Perf< Delegate >:     0.2101452315 [s] {checksum: 0}

[compile_time_function_pointer]
Perf< no_abstraction >: 0.0533959710 [s] {checksum: 0}
Perf< stdex::function<int(int)> >: 0.1576716859 [s] {checksum: 0}
Perf< std::function<int(int)> >: 0.1884306668 [s] {checksum: 0}
Perf< cxx_function::function<int(int)> >: 0.1845623337 [s] {checksum: 0}
Perf< multifunction<int(int)> >: 0.1847705357 [s] {checksum: 0}
Perf< boost::function<int(int)> >: 0.1844458613 [s] {checksum: 0}
Perf< func::function<int(int)> >: 0.1580304572 [s] {checksum: 0}
Perf< generic::delegate<int(int)> >: 0.1585376856 [s] {checksum: 0}
Perf< fu2::function<int(int)> >: 0.1911532853 [s] {checksum: 0}
Perf< fixed_size_function<int(int)> >: 0.1854126428 [s] {checksum: 0}
Perf< embxx_util_StaticFunction >: 0.1866678897 [s] {checksum: 0}
Perf< Function_ >:    0.2034746200 [s] {checksum: 0}
Perf< inplace_function >: 0.1583309923 [s] {checksum: 0}
Perf< Delegate >:     0.1323627700 [s] {checksum: 0}

[compile_time_delegate]
Perf< no_abstraction >: 0.0546856165 [s] {checksum: 0}
Perf< stdex::function<int(int)> >: 0.1580582175 [s] {checksum: 0}
Perf< std::function<int(int)> >: 0.1906249349 [s] {checksum: 0}
Perf< cxx_function::function<int(int)> >: 0.1849874883 [s] {checksum: 0}
Perf< multifunction<int(int)> >: 0.1854241090 [s] {checksum: 0}
Perf< boost::function<int(int)> >: 0.1845475484 [s] {checksum: 0}
Perf< func::function<int(int)> >: 0.1583859094 [s] {checksum: 0}
Perf< generic::delegate<int(int)> >: 0.1584073331 [s] {checksum: 0}
Perf< fu2::function<int(int)> >: 0.2108410486 [s] {checksum: 0}
Perf< fixed_size_function<int(int)> >: 0.1846688487 [s] {checksum: 0}
Perf< embxx_util_StaticFunction >: 0.1865227518 [s] {checksum: 0}
Perf< Function_ >:    0.1851751718 [s] {checksum: 0}
Perf< inplace_function >: 0.1593198010 [s] {checksum: 0}
Perf< Delegate >:     0.1395119443 [s] {checksum: 0}

[heavy_functor]
Perf< stdex::function<int(int)> >: 0.1579305806 [s] {checksum: 0}
Perf< std::function<int(int)> >: 0.1896611708 [s] {checksum: 0}
Perf< cxx_function::function<int(int)> >: 0.1585654459 [s] {checksum: 0}
Perf< multifunction<int(int)> >: 0.2108531183 [s] {checksum: 0}
Perf< boost::function<int(int)> >: 0.1583361219 [s] {checksum: 0}
Perf< func::function<int(int)> >: 0.1845744034 [s] {checksum: 0}
Perf< generic::delegate<int(int)> >: 0.1842995164 [s] {checksum: 0}
Perf< fu2::function<int(int)> >: 0.1584091435 [s] {checksum: 0}
Perf< fixed_size_function<int(int)> >: 0.2105242195 [s] {checksum: 0}
Perf< embxx_util_StaticFunction >: 0.1869382506 [s] {checksum: 0}
Perf< Function_ >:    0.2071549678 [s] {checksum: 0}
Perf< inplace_function >: 0.1854696721 [s] {checksum: 0}
Perf< Delegate >:     0.1586031636 [s] {checksum: 0}

[non_assignable]
Perf< stdex::function<int(int)> >: 0.1844521979 [s] {checksum: 0}
Perf< std::function<int(int)> >: 0.1860469046 [s] {checksum: 0}
Perf< cxx_function::function<int(int)> >: 0.1845928097 [s] {checksum: 0}
Perf< multifunction<int(int)> >: 0.2108033309 [s] {checksum: 0}
Perf< boost::function<int(int)> >: 0.2104690007 [s] {checksum: 0}
Perf< func::function<int(int)> >: 0.1583373289 [s] {checksum: 0}
Perf< generic::delegate<int(int)> >: 0.1647982296 [s] {checksum: 0}
Perf< fu2::function<int(int)> >: 0.2116792880 [s] {checksum: 0}
Perf< fixed_size_function<int(int)> >: 0.1589755133 [s] {checksum: 0}
Perf< embxx_util_StaticFunction >: 0.1867176772 [s] {checksum: 0}
Perf< Function_ >:    0.1863730877 [s] {checksum: 0}
Perf< inplace_function >: 0.1588889134 [s] {checksum: 0}
Perf< Delegate >:     0.1401612932 [s] {checksum: 0}

[lambda_capture]
Perf< stdex::function<int(int)> >: 0.1594558867 [s] {checksum: 0}
Perf< std::function<int(int)> >: 0.1756666764 [s] {checksum: 0}
Perf< cxx_function::function<int(int)> >: 0.1849205015 [s] {checksum: 0}
Perf< multifunction<int(int)> >: 0.2112505126 [s] {checksum: 0}
Perf< boost::function<int(int)> >: 0.1586876514 [s] {checksum: 0}
Perf< func::function<int(int)> >: 0.1578183326 [s] {checksum: 0}
Perf< generic::delegate<int(int)> >: 0.1855617034 [s] {checksum: 0}
Perf< fu2::function<int(int)> >: 0.2103977896 [s] {checksum: 0}
Perf< fixed_size_function<int(int)> >: 0.1852678066 [s] {checksum: 0}
Perf< embxx_util_StaticFunction >: 0.2107188431 [s] {checksum: 0}
Perf< Function_ >:    0.1974609010 [s] {checksum: 0}
Perf< inplace_function >: 0.1851042624 [s] {checksum: 0}
Perf< Delegate >:     0.1584510857 [s] {checksum: 0}

[stateless_lambda]
Perf< stdex::function<int(int)> >: 0.1588940430 [s] {checksum: 0}
Perf< std::function<int(int)> >: 0.1799158079 [s] {checksum: 0}
Perf< cxx_function::function<int(int)> >: 0.1848345050 [s] {checksum: 0}
Perf< multifunction<int(int)> >: 0.2104273603 [s] {checksum: 0}
Perf< boost::function<int(int)> >: 0.1843752537 [s] {checksum: 0}
Perf< func::function<int(int)> >: 0.1583047408 [s] {checksum: 0}
Perf< generic::delegate<int(int)> >: 0.1582446941 [s] {checksum: 0}
Perf< fu2::function<int(int)> >: 0.1841890788 [s] {checksum: 0}
Perf< fixed_size_function<int(int)> >: 0.1860281966 [s] {checksum: 0}
Perf< embxx_util_StaticFunction >: 0.1871841704 [s] {checksum: 0}
Perf< Function_ >:    0.2044821367 [s] {checksum: 0}
Perf< inplace_function >: 0.1845451344 [s] {checksum: 0}
Perf< Delegate >:     0.1324608361 [s] {checksum: 0}

overload.cpp

This shows the timing of each multi-method technique.

Perf< no_abstraction >: 0.0390731812 [s] {checksum: 3}
Perf< stdex::function<Sig...> >: 0.4739417077 [s] {checksum: 3}
Perf< multifunction<Sig...> >: 0.7793043578 [s] {checksum: 3}
Perf< cxx_function::function<Sig...> >: 0.5055884136 [s] {checksum: 3}
Perf< fu2::function<Sig...> >: 0.4742775466 [s] {checksum: 3}
Perf< virtual_base& >: 0.5028338104 [s] {checksum: 3}