Warning(s):

source_file.cpp: In function ‘void conversions(int, unsigned int, float)’:
source_file.cpp:4:5: warning: conversion to ‘int’ from ‘unsigned int’ may change the sign of the result [-Wsign-conversion]
   i = u;
     ^
source_file.cpp:5:5: warning: conversion to ‘unsigned int’ from ‘int’ may change the sign of the result [-Wsign-conversion]
   u = i;
     ^
source_file.cpp:6:5: warning: conversion to ‘int’ from ‘float’ may alter its value [-Wfloat-conversion]
   i = f;
     ^
source_file.cpp:7:5: warning: conversion to ‘float’ from ‘int’ may alter its value [-Wconversion]
   f = i;
     ^
source_file.cpp:8:5: warning: conversion to ‘unsigned int’ from ‘float’ may alter its value [-Wfloat-conversion]
   u = f;
     ^
source_file.cpp:9:5: warning: conversion to ‘float’ from ‘unsigned int’ may alter its value [-Wconversion]
   f = u;
     ^
source_file.cpp: In function ‘int main()’:
source_file.cpp:14:17: warning: negative integer implicitly converted to unsigned type [-Wsign-conversion]
   unsigned u = -42;
                 ^
source_file.cpp:15:11: warning: conversion to ‘int’ alters ‘double’ constant value [-Wfloat-conversion]
   int k = 0.456;
           ^