3
例如,這是boost::tuple
如何聲明可變數量的模板參數?
// - tuple forward declaration -----------------------------------------------
template <
class T0 = null_type, class T1 = null_type, class T2 = null_type,
class T3 = null_type, class T4 = null_type, class T5 = null_type,
class T6 = null_type, class T7 = null_type, class T8 = null_type,
class T9 = null_type>
class tuple;
申報正如預期的那樣,我收到以下錯誤,如果我嘗試使用更多的參數
$ g++ vec.cc
vec.cc: In function 'int main()':
vec.cc:6: error: wrong number of template arguments (12, should be 10)
/usr/include/boost/tuple/detail/tuple_basic.hpp:75: error: provided for 'template<class T0, class T1, class T2, class T3, class T4, class T5, class T6, class T7, class T8, class T9> class boost::tuples::tuple'
vec.cc:6: error: template argument 1 is invalid
vec.cc:6: error: template argument 2 is invalid
vec.cc:6: error: invalid type in declaration before ';' token
$
數量是否有將類聲明的方式以便它接受任意數量的模板參數?
http://en.wikipedia.org/wiki/C%2B%2B11#Variadic_templates – leftaroundabout 2012-03-23 13:18:25
你的意思是說,它的行爲就像是一個C++ 11 std :: tuple? – juanchopanza 2012-03-23 13:19:23
@juanchopanza:...像一個支持可變參數模板的系統中的C++ 11元組意味着什麼?例如VS 2011不支持可變參數模板,我認爲*只要無限大於5,元組就支持無限類型。 – 2012-03-23 13:31:20