Bonus instructions

[mjcaisse]

Including groov/write.hpp results in extra instructions.

Using arm-none-eabi-g++

// #include <groov/write.hpp>
#include <stdx/concepts.hpp>
#include <conc/concurrency.hpp>

struct concurrency_policy {
    template <typename = void, stdx::invocable F>
    static inline auto call_in_critical_section(F &&f, auto &&...) -> decltype(auto) {
        return std::forward<F>(f)();
    }
};

template <> inline auto conc::injected_policy<> = concurrency_policy{};

int main() {}

results in the assembly:

main:
     mov r0, #0 
     bx  lr

Adding groov/write.hpp (uncomment above), results some additional things coming in:

main:
     mov r0, #0 
     bx  lr
_GLOBAL__sub_I_main:
     ldr r3, .L5
     ldr r2, [r3]
     tst r2, #1
     moveq   r2, #1
     streq   r2, [r3]
     bx  lr
.L5:
    .word   guard variable for fmt::v11::format_facet<std::locale>::id

[mjcaisse]

Ah, actually it is caused by either/both fmt/compile.h or fmt/format.h which are transitively included via stdx/static_assert.hpp. Looks like fmt is not acting compile-time only.