Add warning

Author: ikorotkin

docs/solution-manager.md

@@ -76,7 +76,7 @@ public:
 ```
 
 {: .warning }
-Vectors `x_sol` and `t_sol` should be defined before calling the `UserDefinedSolutionManager` constructor and must live until the end of the computation. They shouldn't be passed to the constructor as temporary objects and must **not** go out of scope before finishing the system solving (otherwise, this will lead to dangling references `&m_x_sol` and `&m_t_sol` in the class definition above). 
+Vectors `x_sol` and `t_sol` should be defined before calling the `UserDefinedSolutionManager` constructor and must live until the end of the computation. They shouldn't be passed to the constructor as temporary objects and must **not** go out of scope before finishing the system solving (otherwise, this will lead to dangling references `&m_x_sol` and `&m_t_sol` in the class definition above).
 
 Similar to the mass matrix, vector function and Jacobian matrix definitions, inhereting the `daecpp::SolutionManager` class is a good practice (it serves as a blueprint), but it is not necessary. The user is allowed to define custom Solution Managers without inhereting `daecpp::SolutionManager`.
 
@@ -142,6 +142,9 @@ Constructs Solution class object.
 - `sol` - [`daecpp::SolutionHolder`](#solution-holder-class) object that will store the solution
 - (optional) `t_output` - a vector of output times for writing (`std::vector<double>`)
 
+{: .warning }
+Solution Holder `sol` should be defined before calling the Solution class constructor and must live until the end of the computation. It shouldn't be passed to the constructor as a temporary and must **not** go out of scope before finishing the system solving (the solver writes data to `sol`).
+
 ### Example:
 
 ```cpp