-Wextra
“Aggregator” additional warnings. Includes many interesting things, which is not in (as is the case with , not all possibilities will be considered).
Warns about empty body of conditional expressions or loop . Most often this indicates a typo., changing the logic of the program:
Cm. also .
Warns about “failing” in operator :
The compiler assumes, what the programmer forgot , and shouldn't fail:
In C ++ 17, a special attribute appeared to indicate explicit intent - :
Warns about, that individual members of the structure were not initialized. Most likely they just forgot to do it.:
Warns about unnecessary call in cases, when the compiler does everything by itself, what do you need:
Warns of comparisons, which always have the same result. for example, when an unsigned number is tested for non-negativity. If the programmer makes such a check, then, apparently, suggests, that the number in theory can be negative, However, this is not true. Apparently, he was wrong somewhere:
Warns about shift operations for negative values. Only signed numbers can be negative, but for them it is not correct:
Warns of unused function parameter. maybe, they just forgot about him, and in this case the function may not work correctly.
In C ++ 17, there is an attribute to explicitly express intent :
Warns about, that the value was written to the function parameter, but after that it has never been used. maybe, forgot about him again:
HOW TO RUN YOUR NSD POWER® BALL
Spin NSD Power ball easy and simple, although it takes a little practice to hone the technique. We advise you to do
it's in that order:
1. Insert one end of the lanyard into the connector on the rotor (rice. 1). Wrap the lace around the rotor along the groove
(rice. 2), holding the lace with your fingers and turning the rotor with your thumb. Make sure, that the lace fits into the gutter
smooth, without sagging.
2. Leave the end of the lace approximately 10 centimeters unwound. Hold the NSD tightly
Power ball рукой, which you are going to spin the ball (if you are right handed - right, and if left-handed - left), So, so that
the counter on the upper side of the ball fits snugly against the inside of the palm. In this case, the rotor must be turned
to the ceiling (rice. 3).
3. With your other hand, grasp the loose end of the lace and pull on it, fast and strong (not
restrain yourself, the harder you pull, all the better). If you did everything right, the rotor will spin up to 2400-3000
rpm. Always pull the lace straight out, otherwise it may wind up on the rotor mechanism inside
plastic sphere.
4. Immediately after that, immediately turn your hand over - the rotor should point to the floor. Start rotating the brush
arms (only brush!), holding the ball in slow circular motions. Again: you only need to rotate the hand in the wrist
(rice. 4).
5. The main secret of simple ball spinning is to start with slow movements after a strong pull on the string..
Start with leisurely wide diameter circles 15-20 centimeters, about one circle per second. Don't start fast
short movements of the wrist, otherwise you won't be able to catch the rhythm, and it will be difficult to spin the ball correctly. If you are this
will happen, you will hear clicks inside the sphere - they arise, when the gyroscope is trying in vain to catch the
moment.
6.
The main secret of going to 13 000 rev / m - radius of rotation about 1cm, rotation should be continuous - hand and wrist
look, as if they practically do not move, and the tendons are ready to explode with incredible force.
NSD POWER® BALL - TECHNO Series Functions
In the Techno series, the counter is built into the rotor and has two functions.
1. Maximum rotation speed Start the rotor in this way, so that it starts rotating in the direction of the arrow,
applied to its surface and bring the rotation speed to 6000 rpm. The first of seven diodes, embedded in the surface
the rotor will light up. Adding every thousand revolutions to the speed of rotation will turn on another diode. Counter
writes the rotation record into its memory and after that, how do you set a new record, all diodes will start simultaneously
blink. After, how do you stop ordering effort, hold the sphere in your hands and let the rotor slow down. After
Togo, how the last diode goes out, your result will be displayed directly on the surface of the rotating rotor. (Also you
you will need to learn to hold the sphere level enough to, so that the rotor rotates in one plane and
you could read the result).
2. Number of revolutions per 30 seconds Start the rotor in this way, so that only the first one is lit
diode. Keep this speed around 18 seconds, after which the blue diode will start blinking - this will indicate the beginning
counting. During the next 30 spin the rotor as fast as possible. After, how will this time go, blue
the diode will start to glow constantly. After three seconds, the achieved result will be shown on the rotor surface.
Attention: the counter display on 250Hz and Neon models turns off automatically after 40 seconds after
rotor stops. This allows you to extend the life of the batteries in the meter up to several years
You can replace the batteries
at the nearest watch store.
TECHNO MODEL DOES NOT NEED BATTERIES.
Ignore can't be fixed
Most warnings are not “bzik” compiler, which can be simply ignored. Warning is a potential mistake. A warning is a signal from the compiler that, that one is written, but it is required, perhaps, something completely different.
Therefore, the programmer should help the compiler understand, how to interpret a disputable situation. That is, either correct your mistake, or tell the compiler explicitly that, that you need to believe the programmer and do exactly what, what is written. And this will help not only the compiler, but also to man, which will read the code. An extra one or a couple of parentheses will clearly indicate that, what was meant exactly, what is written.
Next, I will talk about the most important warnings in my opinion and show, what errors can be caught with their help.
Hopefully, that this not too entertaining reading will help to correctly put the comma in the title of this section.
PRECAUTIONS
- People, suffering from heart disease of any kind, the use of this product is not recommended.
- NSD Power ball is suitable for people of all ages, However, use by children before 12 years only recommended
with adult supervision. - Do not touch the rotor rotating at high speed - this may cause burns!
- NEVER drop a ball - a heavy rotor will damage the inner surface or the sphere itself.
- Keep the inside of the sphere clean and avoid any ingress of grease or oil.
- Always hold the sphere tightly, while the rotor spins inside.
If you don't, then your NSD Power ball will become noisy and less smooth to handle.
Remember: low speeds for hand recovery, high speeds - to build muscle!
Lifetime guarantee NSD Power ball is a wonderful and very unique product. When used correctly,
we guarantee, that it will serve you for many years. If you have any questions, which were not covered in this
instructions, you are welcome, contact us at russia @nsdball.with
U.S.A Patent No. 5800311 – Taiwan Patent No. 135058
NSD Power ballwww.nsdball.com/russia/ – [email protected]
HOW TO USE NSD POWER® BALL FOR PHYSICAL EXERCISE
NSD Power ball - incredibly flexible arm muscle trainer, forearms and fingers. Its unique
features make it especially useful for those, who plays golf, tennis, boxing, fencing, rock climbing,
martial arts, shooting, badmintom, as well as cyclocross.
Drummers, guitarists, pianists (but in fact - most musicians) will also benefit from the increased strength and
endurance after training with NSD Power ball. However, for any type of activity, you shouldn't overload yourself
training with NSD Power ball. If you are unsure of your endurance level, see a doctor, or the coach.
NSD Power ball gives resistance, directly proportional to effort, which the user applies. it
means, that at low speeds NSD Power ball is a very effective tool for restoring hands after injuries.
Besides, NSD Power Ball helps relieve inflammation, caused by arthritis, tunnel syndrome or syndrome
repetitive stress (RSI). NSD Power ball has no negative effects.
Ode to the compiler
The compiler is the plus's best friend. A compiler is not just a translator of a formal human-readable language into machine codes. The compiler is the best helper in writing programs.
Important (and not the only one) help, which the compiler provides - search for errors. And I'm not talking about typos, type mismatch and other syntax errors. I'm talking about a huge set of mistakes, which can be caught using the alert mechanism.
I often meet the opinion that, that there are too many warnings, they give false positive results, interfere with work, blur the eyes, distract from “real” errors, etc.. This really happens, but this is very rare.
Need more warnings
But that's not all. There are several flags, which for some reason are not included in any of “argegators”, but extremely important and useful.
Warns about, that the class looks unused, because constructors and destructors are private, and it has no friends and public static member functions.
Similarly, reports, that the class has private member functions, and there are no open ones.
Warns about, that the class has virtual member functions, but the destructor is not virtual. It is very difficult to imagine such a class. Most likely, this is mistake.
Warns about C-style casts. The pros are beautiful and terrible , , and , which are more local and more descriptive. Sishny way too strong and - oh, horror, - unsafe. Better not to use it at all.
Warns about an attempt in a derived class to overload a virtual function of a base class:
Extremely useful flag. Warns about unobvious choice of overloaded function:
Most likely, still wanted to call the second overload, not the first. And if, after all, the first, then be so kind as to say so explicitly.
Warns about, that the branches and are the same:
The conditional operator is also under the gun:
An absolute mystery to me, why is this flag not included?, what in , but in general by default.
Cm. also .
Warns about the same conditions in chains :
Cm. also .
Warns about checking for equality between two floating point numbers. Likely, this is mistake, and the comparison must be carried out with a given accuracy.
Useful option, which does not allow the local variable to be overlapped by another local variable provided, that they are of compatible types.
Warns about pointer conversion, which resets qualifiers. for example, so as not to accidentally lose .
Highly, highly, very important flag. He warns of a huge number of implicit narrowing (that is, potentially leading to loss of information) transformations, which may be the result of a programmer error. for example:
If you've never turned this flag on before, it will be interesting.
Warns about using integer zero instead of .
Flag for pedants. Reports an extra semicolon after the definition of a member function.
How u helps prevent a lot of implicit conversions, which can easily be mistakes:
Warns about suspicious boolean expressions. for example, when instead of bitwise “AND” put a logical “AND”, or boolean expression has the same operands:
Conclusion
To summarize, for the GCC compiler (Clang can't do some of this, Unfortunately) I recommend including the following minimum set of flags, supplementing it with more complex diagnostics if necessary.
Yes, such a list of flags can generate a lot of errors, which may seem redundant at first. But explicit is better than implicit. If you know, what you do - do. But do it like this, so that everyone understands, what exactly did you want. Having worked this way for at least a week, you will understand, how wonderful it is, and you can't go back.
Love your compiler and help it help you write programs.
