View Compilation Error

281388_0_24998.cpp: In constructor `xnum::xnum(char*)':
281388_0_24998.cpp:51: error: no match for 'operator+' in 'operator*(const xnum&, int)(10) + *(str + (+((unsigned int)i)))'
281388_0_24998.cpp: In function `int main()':
281388_0_24998.cpp:87: error: no match for 'operator+' in 'a + i'