'float powf(float, float)' was declared 'extern' and later 'static' [-fpermissive]

[hdelanno]

I have the following error using your library :

DFRobot_TCS34725.cpp:14:14: error: 'float powf(float, float)' was declared 'extern' and later 'static' [-fpermissive]

I think now you could just use the std::powf function instead of defining it yourself, therefore deleting these lines :
https://github.com/DFRobot/DFRobot_TCS34725/blob/main/DFRobot_TCS34725.cpp#L14-L17

[benpaddlejones]

@tangjie133 can you please look at this issue, I get the same error, my school has purchased lots of these so we need the library to work.

[benpaddlejones]

Full error:

C:\...\Documents\Arduino\libraries\DFRobot_TCS34725\DFRobot_TCS34725.cpp: In function 'float powf(float, float)':
C:\...\Documents\Arduino\libraries\DFRobot_TCS34725\DFRobot_TCS34725.cpp:14:14: error: 'float powf(float, float)' was declared 'extern' and later 'static' [-fpermissive]
 static float powf(const float x, const float y)
              ^~~~
In file included from c:\...\appdata\local\arduino15\packages\arduino\tools\arm-none-eabi-gcc\7-2017q4\arm-none-eabi\include\c++\7.2.1\cmath:45:0,
                 from c:\...\appdata\local\arduino15\packages\arduino\tools\arm-none-eabi-gcc\7-2017q4\arm-none-eabi\include\c++\7.2.1\math.h:36,
                 from C:\...\Documents\Arduino\libraries\DFRobot_TCS34725\DFRobot_TCS34725.h:20,
                 from C:\...\Documents\Arduino\libraries\DFRobot_TCS34725\DFRobot_TCS34725.cpp:12:
c:\...\appdata\local\arduino15\packages\arduino\tools\arm-none-eabi-gcc\7-2017q4\arm-none-eabi\include\math.h:365:14: note: previous declaration of 'float powf(float, float)'
 extern float powf _PARAMS((float, float));
              ^~~~

exit status 1

Compilation error: exit status 1

[tangjie133]

Please talk to the new library

[benpaddlejones]

@tangjie133 do you have a link to the new library? Thsi si the one the documentation and Arduino IDE has?