問一個(gè)菜問題---怎么在FREEBSD下用C++？

fantesy

我是個(gè)新手，想在FREEBSD下學(xué)習(xí)C++，已經(jīng)裝了GCC，編譯C程序很正常，可是編譯C++程序就出問題：老是出現(xiàn)如下錯(cuò)誤：
bash-2.05b$ g++ Hello.cpp -o hello
In file included from /usr/include/g++/backward/iostream.h:31,
                 from Hello.cpp:1:
/usr/include/g++/backward/backward_warning.h:32:2: warning: #warning This file includes at least one deprecated or antiquated header. Please consider using one of the 32 headers found in section 17.4.1.2 of the C++ standard. Examples include substituting the <X>; header for the <X.h>; header for C++ includes, or <sstream>; instead of the deprecated header <strstream.h>;. To disable this warning use -Wno-deprecated.
或者是：
bash-2.05b$ g++ file2.C -o file2
file2.C: In function `int main()':
file2.C:5: `cout' undeclared (first use this function)
file2.C:5: (Each undeclared identifier is reported only once for each function
   it appears in.)
file2.C:7: `cin' undeclared (first use this function)
請(qǐng)各位指教，我剛學(xué)，比較菜，如能說詳細(xì)點(diǎn)，不盛感激

無生相

源文件貼出來

stormful

好象是頭文件的缺省目錄不對(duì)。使用/usr/include/g++/試試。

紅袖添香

...


樓主看一下編譯信息，原因和解決的辦法都在這里解釋得很清楚了呀！

bash-2.05b$ g++ Hello.cpp -o hello
In file included from /usr/include/g++/backward/iostream.h:31,
from Hello.cpp:1:
/usr/include/g++/backward/backward_warning.h:32:2: warning: #warning This file includes at least one deprecated or antiquated header. Please consider using one of the 32 headers found in section 17.4.1.2 of the C++ standard. Examples include substituting the <X>; header for the <X.h>; header for C++ includes, or <sstream>; instead of the deprecated header <strstream.h>;. To disable this warning use -Wno-deprecated.
或者是：
bash-2.05b$ g++ file2.C -o file2
file2.C: In function `int main()':
file2.C:5: `cout' undeclared (first use this function)
file2.C:5: (Each undeclared identifier is reported only once for each function
it appears in.)
file2.C:7: `cin' undeclared (first use this function)

wolfop

老問題了，你的程序肯定沒有按照新的C++變種標(biāo)準(zhǔn)寫，cout實(shí)在namespace std中的。