Function rb_vsprintf 

pub unsafe extern "C" fn rb_vsprintf(
    fmt: *const c_char,
    ap: *mut __va_list_tag,
) -> VALUE

Identical to rb_sprintf, except it takes a va_list.

@param[in] fmt A printf-like format specifier. @param[in] ap Contents to format. @return A rendered new instance of ::rb_cString.

Generated by rb-sys for Ruby mri-x86_64-linux-gnu-3.2.3