foo.cc: In function 'void delchar(char*, char)':
foo.cc:6:17: error: 'strlen' was not declared in this scope
    6 |     int i=0,len=strlen(str);
      |                 ^~~~~~
foo.cc:2:1: note: 'strlen' is defined in header '<cstring>'; did you forget to '#include <cstring>'?
    1 | #include <iostream>
  +++ |+#include <cstring>
    2 | using namespace std;
foo.cc: In function 'int main()':
foo.cc:23:12: warning: 'char* gets(char*)' is deprecated [-Wdeprecated-declarations]
   23 |        gets(str);
      |        ~~~~^~~~~
In file included from /nix/store/h5kvfrjmpw792v8jg7nrzfkffmn0iyy8-gcc-12.3.0/include/c++/12.3.0/cstdio:42,
                 from /nix/store/h5kvfrjmpw792v8jg7nrzfkffmn0iyy8-gcc-12.3.0/include/c++/12.3.0/ext/string_conversions.h:43,
                 from /nix/store/h5kvfrjmpw792v8jg7nrzfkffmn0iyy8-gcc-12.3.0/include/c++/12.3.0/bits/basic_string.h:3968,
                 from /nix/store/h5kvfrjmpw792v8jg7nrzfkffmn0iyy8-gcc-12.3.0/include/c++/12.3.0/string:53,
                 from /nix/store/h5kvfrjmpw792v8jg7nrzfkffmn0iyy8-gcc-12.3.0/include/c++/12.3.0/bits/locale_classes.h:40,
                 from /nix/store/h5kvfrjmpw792v8jg7nrzfkffmn0iyy8-gcc-12.3.0/include/c++/12.3.0/bits/ios_base.h:41,
                 from /nix/store/h5kvfrjmpw792v8jg7nrzfkffmn0iyy8-gcc-12.3.0/include/c++/12.3.0/ios:42,
                 from /nix/store/h5kvfrjmpw792v8jg7nrzfkffmn0iyy8-gcc-12.3.0/include/c++/12.3.0/ostream:38,
                 from iostream:39:
/nix/store/y8wfrgk7br5rfz4221lfb9v8w3n0cnyd-glibc-2.37-8-dev/include/stdio.h:605:14: note: declared here
  605 | extern char *gets (char *__s) __wur __attribute_deprecated__;
      |              ^~~~

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